#include <bits/stdc++.h>   using namespace std;   struct tim {     int begin, end;   } t[200005];   int cmp(tim a, tim b) {     if (a.begin != b.begin) return a.begin < b.begin;     return a.end < b.end;   }   int main() {     int n;     cin >> n;     for (int i = 1; i <= n; i++) cin >> t[i].begin >> t[i].end;     sort(t + 1, t + n + 1, cmp);     t[0].end = -1;     int p[3] = {0};     int i;     for (i = 1; i <= n; i++) {       if (t[p[1]].end < t[i].begin) {         p[1] = i;         continue;       }       if (t[p[2]].end < t[i].begin) {         p[2] = i;         continue;       }       break;     }     if (i > n)       cout <<  YES ;     else       cout <<  NO ;   }   