1#include <stdio.h>
2#include <stdlib.h>
3#include <err.h>
4
5int
6main(void)
7{
8	char line[1024];
9	size_t i = 0;
10	while (fgets(line, sizeof(line), stdin) != NULL) {
11		if ((size_t)atoi(line) != i)
12			errx(EXIT_FAILURE, "bad line \"%s\", expected %zu\n",
13			    line, i);
14		i++;
15	}
16	return EXIT_SUCCESS;
17}
18