#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vpii = vector<pair<int, int>>;
using vc = vector<char>;
using vvc = vector<vc>;
long long binpow(long long a, long long n) {
  long long res = 1;
  while (n) {
    if (n & 1) res *= a;
    a *= a;
    n >>= 1;
  }
  return res;
}
bool prime(long long n) {
  for (long long i = 2; i <= sqrt(n); i++) {
    if (n % i == 0) return false;
  }
  return true;
}
int gcd(int a, int b) {
  while (b) {
    a %= b;
    swap(a, b);
  }
  return a;
}
int lcm(int a, int b) { return a / gcd(a, b) * b; }
template <class T>
void Cin_vector(vector<T>& a) {
  for (auto& val : a) {
    std::cin >> val;
  }
}
template <class T>
void Cout_vector(vector<T>& a) {
  for (auto& val : a) {
    std::cout << val << ' ';
  }
}
template <class T>
void Cin_matrix(vector<vector<T>>& a) {
  for (auto& row : a) {
    Cin_vector(row);
  }
}
template <class T>
void Cout_matrix(vector<vector<T>>& a) {
  for (auto& row : a) {
    Cout_vector(row);
    std::cout << "\n";
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int n;
  std::cin >> n;
  vi a(n);
  Cin_vector(a);
  long long sum = 0;
  for (int i = 0; i < n; i++) {
    sum += a[i];
  }
  vi otvet;
  for (int i = 0; i < n; i++) {
    if ((sum - a[i]) / (n - 1) == a[i] && (sum - a[i]) % (n - 1) == 0) {
      otvet.push_back(i + 1);
    }
  }
  std::cout << otvet.size() << "\n";
  Cout_vector(otvet);
}
