#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000005
#define Inf64 4000000000000000001LL

int main(){
	
	int n;
	cin>>n;
	
	set<pair<int,int>> s;
	rep(i,n){
		int a,b;
		cin>>a>>b;
		s.insert({a,b});
	}
	if(s.size()!=n)cout<<"Yes"<<endl;
	else cout<<"No"<<endl;
	
	return 0;
}