#include <bits/stdc++.h>
using namespace std;
const int oo = 0x3f3f3f3f;
const double eps = 1e-9;
const int maxn = 100010;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n, k;
  double l, v1, v2;
  cin >> n >> l >> v1 >> v2 >> k;
  int t = (n + k - 1) / k;
  if (t == 1) {
    cout.precision(17);
    cout << fixed << l / v2 << '\n';
  } else {
    double y = l * (1 + v2 / v1) / (2.0 * t - 1 + v2 / v1);
    double x = l - y;
    double a = y / v2 + x / v1;
    cout.precision(17);
    cout << fixed << a << '\n';
  }
  return 0;
}
