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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n;
    vector<pair<short,short>> a(n);
    for(auto &&[x, y] : a) cin >> x >> y;
    sort(a.begin(), a.end());
    for(int i = 0; i + 1 < n; i++){
        if(a[i] == a[i + 1]){
            cout << "Yes\n";
            return 0;
        }
    }
    cout << "No\n";
}