#include <bits/stdc++.h>
using namespace std;
long double n, l, v1, v2, k, ans;
bool check(long double s) {
  long double x = (n - 1) * s * 2 * v2;
  x /= (v2 + v1);
  x *= v1;
  x = l - x;
  if (x >= s * v2)
    return true;
  else
    return false;
}
int main() {
  cin >> n >> l >> v1 >> v2 >> k;
  n /= k;
  n = ceil(n);
  long double low = 0, high = 1e9;
  for (int i = 0; i < 100; i++) {
    long double mid = (low + high) / 2;
    if (check(mid)) {
      ans = mid;
      low = mid;
    } else
      high = mid;
  }
  long double x = (n - 1) * ans * 2 * v2;
  x /= (v2 + v1);
  x += ans;
  cout << fixed << setprecision(6) << x;
}
