#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  double l, v1, v2;
  cin >> a >> l >> v1 >> v2 >> b;
  double n = (a + b - 1) / b;
  double k = (n - 1) * (v2 - v1) / (v1 + v2) + (n - 1);
  double t1 = l / (v2 + v1 * k);
  printf("%.12f\n", (1 + k) * t1);
  return 0;
}
