#include <bits/stdc++.h>
using namespace std;
long long n, l, v1, v2, k;
long double dn, dl, dv1, dv2, dk;
long long times;
long double x;
double T;
int main() {
  scanf("%lld%lld%lld%lld%lld", &n, &l, &v1, &v2, &k);
  dn = n;
  dl = l;
  dv1 = v1;
  dv2 = v2;
  dk = k;
  times = (n - 1) / k + 1;
  x = l / (v2 * times - (dv2 - dv1) / (dv2 + dv1) * dv2 * (times - 1));
  T = x * (times + (dv2 - dv1) / (dv2 + dv1) * (times - 1));
  printf("%lf\n", T);
  return 0;
}
