func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 3e5 + 10;   int n;   long long a[N];   long long b[N];   int main() {     int t;     scanf( %d , &t);     while (t--) {       vector<pair<long long, long long> > v;       scanf( %d , &n);       v.clear();       for (int i = 0; i < n; i++) {         long long x, y;         scanf( %I64d%I64d , &x, &y);         v.push_back(make_pair(x, y));       }       long long ans = 0;       long long maxx = 0, minn = 1e18 + 10;       long long t;       for (int i = 0; i < n; i++) {         maxx = v[(i + 1) % n].first - v[i].second;         if (maxx < 0) {           maxx = 0;         }         ans += maxx;       }       for (int i = 0; i < n; i++) {         t = v[(i + 1) % n].first - v[i].second;         if (t < 0) {           t = 0;         }         if (minn > ans + v[(i + 1) % n].first - t) {           minn = ans + v[(i + 1) % n].first - t;         }       }       cout << minn << endl;     }     return 0;   }   