#include <bits/stdc++.h>
using namespace std;
int main(int argc, char* argv[]) {
  int n, k;
  double l, v1, v2;
  scanf("%d %lf %lf %lf %d", &n, &l, &v1, &v2, &k);
  int num = n / k;
  if (n % k != 0) num++;
  double a = (v1 + v2) * l / (v1 + v2 + 2 * (num - 1) * v1);
  double out = a / v2 + (l - a) / v1;
  printf("%.7f\n", out);
  return 0;
}
