#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m = 0, i, j = 0, s = 0, t = 0, a[200001], b[200001];
  double aver;
  scanf("%d", &n);
  for (i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    s = s + a[i];
  }
  aver = s * 1.0 / n;
  for (i = 0; i < n; i++) {
    if (a[i] == aver) {
      j = 1;
      t++;
      b[m++] = i + 1;
    }
  }
  if (j) {
    printf("%d\n", t);
    for (i = 0; i < t; i++) printf("%d ", b[i]);
    printf("\n");
  } else
    printf("0\n");
}
