Wanted: English teachers for a school where bats and swallows circle overhead, water drips from the ceiling and there are not enough classrooms.
"Many young people come to teach, but most don't want to stay a long time," complains Yang Zaide, the 55-year-old headteacher in the village of Purple Cloud in southern China's Ghizhou region.
But then that may be because this is no ordinary school - it is inside a mountain of limestone.
More than 150 children attend the primary in Middle Cave, an eight-storey high, 250-yard cavern in which 83 people also live.
Some of the pupils are cave inhabitants, others come from the surrounding area. Eight who have to travel too far live in a shack inside the rocky hollow during the week.
Families here eke out a simple life tending mountain fields, raising pigs, cows and chickens. They collect water that drips from the rock for drinking and cook using firewood gathered on the mountain slopes.
But there are surprising amenities - computers, satellite television, refrigerators and a telephone. They were financed in part by Frank Beddor, 81, a businessman in Minneapolis, after he was prompted by a newspaper article three years ago to visit with a friend.
Villagers say the donations helped them install an electricity system and hire four teachers at the cave's primary school.
"The main role we are playing is to get them well educated so they will be equipped to enter China's dynamic work force," Mr Beddor said.
"We are currently working to get more English teachers to teach English to the students."
Eighteen thatched-bamboo homes, all roofless to let in more light, are clustered near the mouth of the cave. At the back is the village primary school with three classrooms and an office.
The teachers who stay tend to have roots in Ghizhou, a region 1,000 miles south-west of Beijing which is one of China's poorest.
Wang Lian, 23, grew up in a village five hours' walk from Middle Cave and has taught here for two years. She tried life in the booming coastal province of Guangzhou but came back to help.
"When I was young, I lived an even harder life than the children here. I went to school in bare feet," she said. "I was helped by other people. This is a chance for me to repay them."