#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, k;
  long double l, v1, v2;
  cin >> n >> l >> v1 >> v2 >> k;
  m = (n + k - 1) / k;
  long double tmp = l / (v2 + 2 * (m - 1) * v1 * v2 / (v1 + v2));
  tmp = tmp * (1 + (m - 1) * 2 * v2 / (v1 + v2));
  printf("%.9f\n", (double)tmp);
}
