#include <bits/stdc++.h>
using namespace std;
const long long inf = (long long)1e9;
const long long MOD = (long long)1e9 + 7;
const long long P = 239;
const long long MAX_N = 1000;
const long long CNT = 5;
const long double pi = 3.1415926535897932384626;
const long double eps = 1e-6;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  long long n, l, v1, v2, k;
  cin >> n >> l >> v1 >> v2 >> k;
  long long cnt = (n + k - 1) / k;
  long double f = (long double)(v2 - v1) / (v2 + v1);
  long double t = (long double)l / (v2 * cnt - v2 * (cnt - 1) * f);
  cout.precision(30);
  t = t * cnt + t * f * (cnt - 1);
  cout << t;
  return 0;
}
