#include <bits/stdc++.h>
using namespace std;
int a[200005], store[200005];
int main() {
  int n, sum, i, z, k;
  cin >> n;
  sum = 0;
  for (i = 0; i < n; i++) {
    cin >> a[i];
    sum += a[i];
  }
  k = 0;
  for (i = 0; i < n; i++) {
    if ((sum - a[i]) % (n - 1) == 0) {
      if ((sum - a[i]) / (n - 1) == a[i]) store[k++] = i + 1;
    }
  }
  printf("%d\n", k);
  for (i = 0; i < k; i++) printf("%d ", store[i]);
  printf("\n");
  return 0;
}
