Until the tsunami arrived Saiful was the caretaker of Banda Aceh's junior high school three. He was responsible for tidying up. But on Wednesday he found himself giving a class in religious education.
"I'm teaching the students about 7th-century Islam," he said.
But did he know anything about it?
"Oh yes. I used to be a student myself."
Saiful's sudden elevation from caretaker to teacher is scarcely surprising. Of the school's staff of 91 teachers, at least 17 are missing or dead. The tsunami killed the biology and Indonesian teachers, two administrative staff and the hard-working deputy head, Yusuf Syam, together with his family. It also killed more than 150 of the 1,276 pupils.
The headteacher, Bukhari, said: "We don't know anything for sure, but 15 per cent of my pupils appear to be dead."
On Wednesday a few hundred of the survivors, aged 12 to 15, turned up for lessons. They arrived at 8am, the girls wearing white headscarves, the boys -- a few of them on chopper-style bicycles -- in blue trousers and white shirts. They stood in the courtyard before trooping down the nearest corridor.
Normally the students would have filled 20 classrooms. On Wednesday they fitted comfortably into three. By 8:30am the lessons had begun. Next door to Saiful's religious education class Zuraida was teaching algebra.
"There are so few students here that the classes have all been mixed up," she said.
On a nearby wall the parents of a missing pupil have posted his photograph and some telephone numbers.
"There were 43 students in my class," Rizky Syamputra, 12, said. "Now there are just two of us, me and my friend Arik."
What had happened to the others? "I don't know,'"he said.
Throughout Aceh it is the same dismal story. The deputy governor of the Sumatran province, Azwar Abubakar, said 420 school buildings had fallen apart and about 1,044 teachers had been killed. An unknown number of students are dead or missing.
Junior high school three, which reopened on Monday, is currently the only school functioning in Banda Aceh. Each day more pupils drift back. Officials have announced that the other schools should restart on Jan. 26, a month after the disaster.
But the edict seems optimistic. Many schools no longer exist; others have become temporary refugee camps; some are still full of debris and bodies.
"We're trying to start the education process again," Bukhari said.
"But it's difficult. Some of the students are now living in other districts or are in refugee camps. And some are dead. Many of them have also lost all their books and uniforms. I'm going to try and buy them some more from my own money."
The tsunami came to within 100m of the school's grounds before it stopped. Saiful said there was no doubt that many pupils were still traumatized.
"The mood of the students is good enough. They want to study. But they are still scared. I can tell it from their faces," he said.