func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     pair<int, int> a[555555];     double n, k, t, l = -1, r = 1e12, c, maxx, yes = 0;     int i;     cin >> n;     for (i = 0; i < n; i++) scanf( %d%d , &a[i].first, &a[i].second);     for (k = 0; k < 300; k++) {       maxx = -1e30;       c = (l + r) * 0.5;       t = 0;       for (i = 0; i < n; i++)         if (a[i].second > 0)           maxx = max(maxx, a[i].first + a[i].second * c);         else if (maxx >= a[i].first + a[i].second * c) {           t = 1;           break;         }       if (t) {         yes = 1;         r = c;       } else         l = c;     }     cout.precision(20);     if (yes == 0) r = -1;     cout << r;     return 0;   }   