#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
using namespace std;
long long int n, l, v1, v2, k;
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ;
  cin >> n >> l >> v1 >> v2 >> k;
  if (n == k) {
    cout << fixed << setprecision(8)
         << (long double)((long double)l / (long double)v2) << '\n';
    return 0;
  }
  long long int x = (n + k - 1) / k;
  long double a, b;
  a = v1;
  b = v2;
  long double t = 1;
  for (long long int i = 0; i < x - 1; i++) {
    long double res = (b - a) * v1 / (v1 + v2);
    long double d = res / v1;
    t += d;
    a += d * v1;
    b += d * v1;
    d = (b - a) / (long double)(v2 - v1);
    t += d;
    a += d * v1;
    b += d * v1;
  }
  cout << fixed << setprecision(8) << t * (long double)(l / b) << '\n';
}
