func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int N;     scanf( %d , &N);     int P;     scanf( %d , &P);     vector<int> As, Bs;     long long SA = 0, SB = 0;     for (decltype(N) _i = 0, _n = (N); _i < _n; _i++) {       int A;       scanf( %d , &A);       int B;       scanf( %d , &B);       As.push_back(A);       Bs.push_back(B);       SA += A;       SB += B;     }     auto check = [&](double t) {       double tmp = 0.0;       for (decltype(N) i = 0, _n = (N); i < _n; i++) {         tmp += max(As[i] * t - Bs[i], 0.0) / P;       }       return tmp <= t;     };     if (SA <= P) {       printf( -1 n );     } else {       double l = 0.0, r = SB * 2.0;       int cnt = 0;       while (1e-10 < (r - l) and cnt < 1000) {         cnt++;         double c = (l + r) / 2;         if (check(c)) {           l = c;         } else {           r = c;         }       }       printf( %f , l);     }     return 0;   }   