#include <bits/stdc++.h>
int n, m, k;
double v1, v2, len, t, tt;
int main() {
  scanf("%d%lf%lf%lf%d", &n, &len, &v1, &v2, &k);
  m = (n - 1) / k + 1;
  tt = len / (v2 + (m - 1) * 2 * v1 * v2 / (v1 + v2));
  printf("%.8lf\n", (len + (v1 - v2) * tt) / v1);
  return 0;
}
