func_code_string: #include <bits/stdc++.h>   using namespace std;   long long cou = 0, ans = 0, mx = INT_MIN, mn = INT_MAX, sum = 0, modu = 1e9 + 7;   vector<vector<int>> from, to;   vector<bool> visited(1e3, false);   void dfs(int t) {     visited[t] = true;     for (int c = 0; c < from[t].size(); c++) {       if (!visited[from[t][c]]) dfs(from[t][c]);     }   }   void d(int t) {     dfs(t);     for (int z = 0; z < to[t].size(); z++) {       if (!visited[to[t][z]]) d(to[t][z]);     }   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     ;     int t;     cin >> t;     vector<pair<int, int>> v(t);     for (long long i = 0; i < t; i++) cin >> v[i].first >> v[i].second;     sort(v.begin(), v.end());     if (t < 3) {       cout <<  YES ;       return 0;     }     int n1 = v[0].second, n2 = v[1].second;     for (int x = 2; x < t; x++) {       if (n1 >= v[x].first && n2 >= v[x].first) {         cout <<  NO ;         return 0;       } else {         if (n1 < n2)           n1 = v[x].second;         else           n2 = v[x].second;       }     }     cout <<  YES ;     return 0;   }   