#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
const int S = 100003;
const int MOD = 1000000007;
int _I(){int x; scanf("%d", &x); return x;}
LL _LL(){LL x; scanf("%lld", &x); return x;}
int dirX[]={1, 0, -1, 0, 1, -1, 1, -1};
int dirY[]={0, 1, 0, -1, 1, -1, -1, 1};
int rX[] = {1, 1, 2, 2, -1, -1, -2, -2};
int rY[] = {2, -2, 1, -1, 2, -2, 1, -1};

int Set(int N, int pos){return N=N|(1<<pos);}
bool Check(int N, int pos){return (bool)(N&(1<<pos));}
int Reset(int N, int pos){return N=N&~(1<<pos);}
///...............Code Starts From Here...............///

map <int, int> M, N;

void Do(){
    int n = _I();
    int mxx = -100, mxy = -100;
    int ans = 0;
    M.clear(), N.clear();
    for(int i = 0; i < n; i++){
        int x = _I();
        int y = _I();
        M[x]++;
        N[y]++;
        mxx = max(mxx, M[x]);
        mxy = max(mxy, N[y]);
    }
    if((mxy == n) || (mxx == n))ans = 1;
    if(ans)cout << "YES" << endl;
    else cout << "NO" << endl;
}

int main(){
    Do();
    return 0;
}