#include <bits/stdc++.h>
int a[200005], bil[200005];
long long n, jumlah, b;
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; ++i) {
    scanf("%d", &a[i]);
    jumlah += a[i];
  }
  for (int i = 1; i <= n; i++) {
    if ((jumlah - a[i]) / (n - 1) == a[i] && (jumlah - a[i]) % (n - 1) == 0) {
      ++b;
      bil[b] = i;
    }
  }
  printf("%d\n", b);
  for (int i = 1; i <= b; ++i) {
    if (i == b) {
      printf("%d\n", bil[i]);
    } else {
      printf("%d ", bil[i]);
    }
  }
}
