At dawn, with a bullhorn in her left hand, Zhang Guimei tiptoes out of her dormitory and clutches at the handrail as she slowly makes her way down the stairs.
Minutes later, a colleague drives her to a nearby building on an electric motorcycle.
"Hurry up! Time to get up, girls!" Zhang yells on the top floor of the four-story teaching building, shattering the silence that envelops the school.
The call always comes at 5:30 every morning, pulling the young girls from their beds and urging them to begin reading in their classrooms, where Zhang has already switched on the lights and sat waiting for them.
Zhang, 63, is the principal of the Huaping Senior High School for Girls and the president of a home for homeless children in Huaping County in the city of Lijiang, southwest China's Yunnan Province.
When Zhang first came to the county in 1996, little did she know she would stay here for more than 20 years, never mind become a "mom" for more than 130 abandoned children or even establish a girls' school.
Zhang was born in northeast China's Heilongjiang Province and came to Yunnan at the age of 17 and was later admitted to Lijiang Teachers College. After graduation, she worked as a teacher in the city of Dali, together with her husband.
In 1994, her husband died of stomach cancer. The heartbroken Zhang asked to transfer to a remote school in Huaping to escape these memories two years later.
However, misfortune befell her once again -- she was diagnosed with fibroids in her uterus. Zhang could no longer afford surgery and other further treatment as her husband's medical bills had left her penniless.
After a tear-filled night, she decided to keep the secret to herself.
Zhang continued to give lectures as usual. It was not until the end of the senior high school entrance examination a few months later that she told her school she was ill. With the help of the county, she underwent an operation.
Zhang did not expect that her students would venture into the mountains to pick wild walnuts for her as a nutritional supplement. Moreover, their parents went to collect glossy ganoderma, an expensive and rare traditional Chinese medicine, and ground it into a powder for her.
"They told me that it could cure my illness," she said.
Fortunately, the women's federation of Huaping was aware of her situation and initiated a donation for her. One local resident donated the five yuan (about 70 U.S. cents) she had set aside to pay for her trip home, instead making the journey by foot over several hours in a bid to lend a helping hand to Zhang.
"The county is benevolent to me, only when I live well can I repay the debt," she recalled.
Zhang found that some of the school-aged girls in Huaping did not continue to pursue senior high school education after finishing their nine-year compulsory education, covering primary school and junior high school.
These girls came back to their hometowns to do farm work or part-time work to support their families. Their parents would rather keep them at home instead of sending them to further schooling due to their traditional views and poor family conditions.
"We often say that every child should have an equal start, but these girls don't even have a chance to approach the starting line," she noted.
Faced with such a depressing situation, she decided to establish a senior high school exclusively for girls that does not charge tuition fees. Every girl who wishes to read and learn can come here.
"Education for girls will influence three future generations," said Zhang, adding that it is of prime importance for girls to receive education and break the vicious circle of poverty and lack of education being handed down from mother to child.
It took five years, countless classes, unremitting efforts to attract donations, frequent suspicion from others and her own self-doubt until she got a chance to see her dream come true.
In 2007, knowing of Zhang's frugality and lack of formal wear, the local government disbursed a grant for her to buy a new outfit before she headed to Beijing to attend the 17th National Congress of the Communist Party of China. However, she left the money to the home for homeless children.
One day on her way to a panel discussion, a friendly journalist pulled Zhang aside and asked whether she knew there were two prominent holes in the rear of her jeans, apparently a sign of wear and tear rather than a fashion statement.
It was Zhang's favorite pair of jeans cherished for their sturdiness. She often sat on the ground when she grew tired while visiting the homes of her students, and over the years, they had evidently worn through. "In that moment, I just wanted to crawl under a rock," she said.
She and the reporter chatted till late into the night. Zhang cried and mentioned her dream of establishing a senior high school exclusively for girls. The reporter then wrote and reported a story based on Zhang's account, which soon made headlines across the country.
In quick succession, the local governments of Lijiang and Huaping allocated 2 million yuan to support Zhang's plan, helping her build a school for girls and support its operation.
It is Huaping Senior High School for Girls, the first free public high school of its kind in the country. Zhang prefers to call the students "mountain girls" instead of girls from impoverished households, to protect their privacy and self-esteem.
The school was opened in September 2008, with no walls, canteens or even a washroom.
About six months later, nine of its 17 teachers resigned and six of its 100 students quit because of the harsh conditions and heavy pressure.
However, the remaining teachers offered to stay. They supported their students with single-hearted devotion and thereafter improved the quality of teaching at the school.
Thanks to their continuous efforts, the school became an educational miracle in Yunnan. Last year, the school's university admission rate ranked first among all senior high schools in Lijiang.
Beset by multiple diseases including cerebellar atrophy and bone tumors, Zhang had to give up teaching and now works in a supporting role at the school.
Zhang told some of her colleagues that after she died, they only needed to scatter her ashes in the Jinsha River, the upper reaches of the Yangtze, China's longest river.
Although she no longer needs to worry about the school's finances, Zhang keeps her habit of saving and has donated more than 1 million yuan to subsidize students in the girls' school and a local primary school in recent years.
On one hand, Zhang seems to have nothing: no family, no kids, no savings, no house, not even a laptop.
On the other hand, more than 130 homeless children call her "Mom"; and she has fostered a total of 1,645 female students over more than a decade.
According to Zhang, every year she encourages girls to study harder to get into good universities through the annual national college entrance exam, known as the gaokao. She also tells them that life is more than just the gaokao.
The girls never let her down. Some of them have even taken the "baton" from her and run with it.
Zhou Yunli is among the first group graduating from the girls' high school. After graduating from junior high school, Zhou and her sister both qualified for senior high school enrolment. However, their father was still trying to eke out a basic living and provide for them, with the prospect of further schooling never in the conversation.
Zhou's sister offered to work as a migrant worker to support the family and let her sibling pursue higher education.
The founding of the girls' school marked a turning point for them. They were then enrolled by the school and admitted to universities three years later. After graduating from Yunnan Normal University in 2015, Zhou came back and worked as a math teacher at the girls' school.
Zhou said she returned to her alma mater with gratitude. "I'm grateful that the school offered me an opportunity to get further schooling so I am willing to use what I have learned to help children in the same situation as me."
"What do I expect from them? It's not that they must go to prestigious universities. I hope they become stronger one day so they can lend a helping hand to those in need," Zhang said.