int n = 1024;
unsigned int i;
for (i = INT_MAX; ; i++) {
    int a;
    int m = 0;
    for (a = m + 1; a <= n; a++)
        m = (m + i) % a;
    if (m == 6)
        break;
}
i--;
printf("The smallest number is %d or %u\n", (int)i, i);