func_code_string: #include <bits/stdc++.h>   using namespace std;   bool same(int l1, int r1, int l2, int r2) {     if (r1 < l2 || r2 < l1) {       return 0;     }     return 1;   }   signed main() {     int q;     cin >> q;     while (q--) {       int n;       cin >> n;       int l = 1e9 + 5, r = 0;       for (int i = 0; i < n; i++) {         int l3, r3;         cin >> l3 >> r3;         r = max(r, l3);         l = min(l, r3);       }       cout << max(0, r - l) <<   n ;     }     return 0;   }   