#include <cstdio>
#include <algorithm>

using namespace std;

int a[11], b[11];

int main () {
    freopen ("trick.in", "r", stdin);
    freopen ("trick.out", "w", stdout);
    int n;
    scanf("%d ", &n);
    for (int i = 0; i < n; i++) {
        scanf("%d %d", &a[i], &b[i]);
        if (a[i] > b[i])
            swap(a[i], b[i]);
    }
    for (int k = 0; k < n - 1; k++) {
            if (a[k + 1] < a[k] || b[k + 1] < b[k]) {
                printf("NO");
                return 0;
            }
    }
    printf("YES");
    return 0;
}