#include <iostream>
#include <vector>
using namespace std;
vector<int> c ( 10e6+1, 0);
vector<int> numbers;
vector<int> indices;
int main(){
int total = 0;
int n;
cin >> n;
int temp;
for(int i =0; i < n; i++){
cin >> temp;
numbers.push_back(temp);
total+=temp;
c[temp]++;
}
for(int i =0; i < numbers.size(); i++){
c[numbers[i]]--;
if((total - numbers[i]) % 2 == 0){
temp = total-numbers[i];
temp/=2;
if(c[temp] > 0) indices.push_back(i);
}
c[numbers[i]]++;
}
cout << indices.size() << endl;
for(int i =0; i < indices.size(); i++){
cout << (indices[i] + 1 ) << " ";
}
cout << endl;
return 0;
}
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