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

#include<atcoder/all>
using namespace atcoder;
using mint=atcoder::modint1000000007;

#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#define int long long

#define rep(i,n) for(int i=0;i<(n);i++)
#define rng(i,l,r) for(int i=(l);i<(r);i++)
#define rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define rrng(i,l,r) for(int i=(r)-1;i>=(l);i--)

#define fi first
#define se second
#define all(x) (x).begin(),(x).end()

struct fast_io{fast_io(){std::cin.tie(nullptr)->sync_with_stdio(false);}}_;

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