#include <bits/stdc++.h>
using namespace std;
int main() {
  double n, l, v1, v2, k;
  cin >> n >> l >> v1 >> v2 >> k;
  double t = l / (v2 + v1 * (ceil(n / k) - 1) * ((2 * v2) / (v1 + v2)));
  cout << setprecision(10)
       << (1 + (ceil(n / k) - 1) * ((2 * v2) / (v1 + v2))) * t << endl;
}
