#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/stat.h>
#include <fcntl.h>

int
main(int argc, char *argv[])
{
    int fd = open(argv[1], O_RDWR);

    off_t min_ind = -1;
    long long min, tmp;
    for (off_t cnt = 0; read(fd, &tmp, sizeof(tmp)) == sizeof(tmp); cnt += sizeof(tmp)) {
        if (min_ind == -1 || tmp < min) {
            min = tmp;
            min_ind = cnt;
        }
    }

    lseek(fd, min_ind, SEEK_SET);

    min = -min;
    if (write(fd, &min, sizeof(min)) < sizeof(min)) {
        return 1;
    }

    close(fd);
    return 0;
}