#include <bits/stdc++.h>
using namespace std;
int main() {
  double n, l, v1, v2, k, num, x1, x2, res, x3;
  int a1, a2;
  cin >> n >> l >> v1 >> v2 >> k;
  a1 = n;
  a2 = k;
  num = (a1 / a2) + (bool)(a1 % a2) - 1;
  x3 = 2 * num + 1;
  x3 = x3 * v1 / (2 * v2);
  x3 += 0.5;
  x2 = l / x3;
  x1 = x2 * v1 / v2;
  res = (x1 / v1) * num;
  res += ((x1 + x2) / 2) / v2;
  cout << setprecision(11) << res << endl;
  return 0;
}
