#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353;
int n;
int l[210], r[210], mid[210];
int b[610];
int cnt = 0;
int dp[610];
int power(int a, int b) {
    long long res = a, ans = 1;
    for (; b; b >>= 1, res = res * res % mod) if (b & 1) ans = ans * res % mod;
    return ans;
}
int main() {
    scanf("%d", &n);
    for (int i = 1; i <= n; i++) scanf("%d%d", l + i, r + i), mid[i] = (l[i] + r[i]) / 2;
    for (int i = 1; i <= n; i++) {
        b[++cnt] = l[i], b[++cnt] = r[i], b[++cnt] = mid[i];
    }
    sort(b + 1, b + 1 + cnt);
    cnt = unique(b + 1, b + 1 + cnt) - b - 1;
    b[0] = -100;
    dp[0] = 1;
    for (int i = 1; i <= cnt; i++) {
        for (int j = 0; j < i; j++) {
            int cnt = 0, tag = 0;
            for (int k = 1; k <= n; k++) if (b[j] < l[k] && b[i] >= r[k]) cnt++;
            for (int k = 1; k <= n; k++) if (b[j] >= l[k] && b[j] < mid[k] && b[i] >= mid[k] && b[i] < r[k]) tag = 1;
            if (tag) continue;
            dp[i] = (dp[i] + 1ll * (mod - dp[j]) * power(2, cnt)) % mod;
        }
        int tag = 0;
        for (int j = 1; j <= n; j++) if (b[i] >= l[j] && b[i] < r[j]) tag = 1;
        if (tag == 0 && i != cnt) dp[i] = 0;
    }
    puts(dp[cnt] ? "YES" : "NO");
}