#include <bits/stdc++.h>
using namespace std;

int main(){
    int N;
    cin >> N;
    set<pair<int, int>> S;
    for(int i = 0; i < N; i++){
    	int a, b;
    	cin >> a >> b;
    	S.insert(make_pair(a, b));
    }
    if(S.size() == N) cout << "No" << endl;
    else cout << "Yes" << endl;
    return 0;
}