#include <stdio.h>
#include <string.h>
#define N 10
int main() {
int i = 0;
int f[N] = {0};
// 1 3 6 10 15 21
int d = 0;
for (i = 0; i < N; i++) {
f[d] = 1;
d++;
d += i;
d %= N;
printf("d = %d\n", d);
}
for (i = 0; i < N; i++) {
if (!f[i]) {
printf("rabbit maybe in %d hollow\n", i);
}
}
printf("\n");
return 0;
}