#include <bits/stdc++.h>
using namespace std;
using LL = long long;
using PII = pair<int, int>;
int main() {
  int n, l, v1, v2, k;
  cin >> n >> l >> v1 >> v2 >> k;
  int m = (n + k - 1) / k;
  double x = (double)(v1 + v2) * l / ((2 * m - 1) * v1 + v2);
  printf("%.10f\n", x / v2 + (l - x) / v1);
}
