#include <bits/stdc++.h>
int main() {
  int n, k;
  double x;
  double l, v1, v2;
  double answer = 0;
  double sp = 0;
  scanf("%d %lf %lf %lf %d", &n, &l, &v1, &v2, &k);
  x = n / k + (n % k != 0);
  double d = l / ((x - 1) * v1 / v2 + 1.0 +
                  v1 * (1.0 - v1 / v2) / (v1 + v2) * (x - 1));
  printf("%.10lf\n", d / v2 + (l - d) / v1);
}
