#include <bits/stdc++.h>
using namespace std;
const double g = 10.0, eps = 1e-12;
const int N = 100000 + 10, maxn = 1200000 + 10, inf = 0x3f3f3f3f,
          INF = 0x3f3f3f3f3f3f3f3f;
int main() {
  long long n, l, v1, v2, k;
  scanf("%lld%lld%lld%lld%lld", &n, &l, &v1, &v2, &k);
  long long te = n / k - 1;
  if (n % k != 0) te++;
  double low = 2.0 * v1 / (v1 + v2) * v2;
  double t1 = (double)l / (low * te + v2);
  double t2 = (double)(v2 - v1) / (v1 + v2) * t1;
  double ans = (double)te * (t1 + t2) + t1;
  printf("%.12f\n", ans);
  return 0;
}
