#include <bits/stdc++.h>   using namespace std;   int n, k, v1, v2, L;   bool can(double m) {     double bus = 0, nbus = 0;     for (int i = 0; i < (n + k - 1) / k; i++) {       if (i == 0)         bus += m * v2;       else         bus += m * v1;       nbus += m * v1;       if (bus > L) return false;       double sb = (bus - nbus) / (v1 + v2);       bus += sb * v1;       nbus += sb * v1;     }     return true;   }   int main() {     scanf( %d%d%d%d%d , &n, &L, &v1, &v2, &k);     double l = 0, r = (double)L / v2, m;     for (int i = 0; i < 100; i++) {       m = (l + r) / 2.0;       if (can(m))         l = m;       else         r = m;     }     printf( %.12f , m + (L - m * v2) / v1);   }   