#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <map>
using namespace std;
int main() {
    int n;
    map<int, int> a;
    while (cin >> n) {
        a[n]++;
        if (a[n] == 1) {
            cout << "NO\n";
        } else {
            cout << "YES\n";
        }
    }
    return 0;
}