#include <bits/stdc++.h>
using namespace std;
const int MaxN = 200000 + 5;
int N;
double A[MaxN];
vector<int> X;
int main(void) {
  scanf("%d", &N);
  for (int i = 0; i < N; i++) scanf("%lf", &A[i]);
  double Sum = 0;
  for (int i = 0; i < N; i++) Sum += A[i];
  for (int i = 0; i < N; i++)
    if (A[i] == (Sum - A[i]) / (N - 1)) X.push_back(i + 1);
  printf("%d\n", X.size());
  int Sz = X.size();
  for (int i = 0; i < Sz; i++) printf("%d%c", X[i], (i + 1 == Sz) ? '\n' : ' ');
  return 0;
}
