#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  double L, v1, v2;
  cin >> n >> L >> v1 >> v2 >> k;
  double p = 2 * (n / k - (n % k == 0)) + 1;
  printf("%.10f", double(L * (p * v2 + v1)) / double(v2 * (p * v1 + v2)));
}
