func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, l[2005], r[2005], t, k;     cin >> t;     while (t) {       int q = 0, next = 0;       cin >> n;       for (int i = 0; i < n; i++) {         cin >> l[i] >> r[i];         if (i == 0) {           next = l[i] + 1;           cout << l[i] <<    ;           continue;         }         if (r[i] < next) {           cout << 0 <<    ;         } else if (l[i] <= next) {           cout << next <<    ;           next++;         } else {           cout << l[i] <<    ;           next = l[i] + 1;         }       }       cout << endl;       t--;     }     return 0;   }   