#include <bits/stdc++.h>
#define int long long
using namespace std;
signed main() {
    int n;cin>>n;
    set<pair<int,int>>ls;
    for(int i=0;i<n;i++){
        int a,b;cin>>a>>b;
        ls.insert(make_pair(a,b));
    }
    cout<<(ls.size()==n?"No":"Yes")<<endl;
}