#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:167177216")
using namespace std;
const int INF = 1e9;
const long double eps = 1e-9;
const long long mod = INF + 7;
const int dx[] = {-1, -1, 0, 1, 1, 1, 0, -1};
const int dy[] = {0, 1, 1, 1, 0, -1, -1, -1};
int n, s, a[222222];
vector<int> ans;
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) {
    scanf("%d", &a[i]);
    s += a[i];
  }
  for (int i = 1; i <= n; i++) {
    if ((s - a[i]) % (n - 1) == 0 && (s - a[i]) / (n - 1) == a[i])
      ans.push_back(i);
  }
  printf("%d\n", (int)(ans.size()));
  for (int i = 0; i < ans.size(); i++) printf("%d ", ans[i]);
  printf("\n");
  return 0;
}
