#include <bits/stdc++.h>
using namespace std;
int n, s;
int t[200010];
vector<int> sol;
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) scanf("%d", &t[i]), s += t[i];
  for (int i = 1; i <= n; i++) {
    int ss = s - t[i];
    if (ss % (n - 1) == 0 && ss / (n - 1) == t[i]) sol.push_back(i);
  }
  printf("%d\n", sol.size());
  for (int i = 0; i < (int)sol.size(); i++) printf("%d ", sol[i]);
  return 0;
}
