#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cout.precision(8);
  cout << fixed;
  int n, k;
  double L, v1, v2;
  cin >> n >> L >> v1 >> v2 >> k;
  if (n == k) {
    cout << L / v2;
    return 0;
  }
  --n;
  double N = double(n / k + 1);
  double M = (v1 + v2) / (2 * v1);
  double X = L / ((N - 1) / M + 1);
  cout << (L - X) / v1 + X / v2;
  return 0;
}
