#include <bits/stdc++.h>
using namespace std;
int main() {
  const int N = 200005;
  int n, a[N], ans[N], sum = 0;
  scanf("%d", &n);
  for (int i = 0; i < n; ++i) {
    scanf("%d", a + i);
    sum += a[i];
  }
  int cnt = 0;
  for (int i = 0; i < n; ++i) {
    if (a[i] * (n - 1) == (sum - a[i])) {
      ans[cnt++] = i + 1;
    }
  }
  printf("%d\n", cnt);
  bool flag = 0;
  for (int i = 0; i < cnt; ++i) {
    if (flag) putchar(' ');
    printf("%d", ans[i]);
    flag = 1;
  }
}
