#include <cstdio>
#include <iostream>
#define MAXN 15
using namespace std;

int n;
pair<int, int> v[MAXN];

int main() {

    scanf("%d", &n);
    for(int i = 1; i <= n; ++i)
        scanf("%d %d", &v[i].first, &v[i].second);

    bool ok = 1;
    for(int i = 2; i <= n; ++i)
        if(v[i].first != v[i - 1].first)
            ok = 0;

    if(ok == 1)
        return 0 * printf("YES\n");

    ok = 1;
    for(int i = 2; i <= n; ++i)
        if(v[i].second != v[i - 1].second)
            ok = 0;

    if(ok == 1)
        return 0 * printf("YES\n");

    printf("NO\n");

    return 0;
}