#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int T = 1;
  while (T--) {
    int n, k;
    double l, v1, v2, d, r, res;
    cin >> n >> l >> v1 >> v2 >> k;
    if (n % k == 0)
      r = n / k;
    else
      r = n / k + 1;
    d = l / (1 + 2 * (r - 1) * v1 / (v1 + v2));
    res = d / v2 + (l - d) / v1;
    printf("%.8lf", res);
  }
}
