func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAXN = 5010;   const int mod = 1e9 + 7;   const int INF = 0x3f3f3f3f;   const double pi = acos(-1.0);   const double eps = 1e-4;   int main() {     double d, l, v1, v2;     cin >> d >> l >> v1 >> v2;     printf( %.6lf n , (l - d) / (v1 + v2));     return 0;   }   