#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, l, v1, v2, k;
  while (scanf("%d%d%d%d%d", &n, &l, &v1, &v2, &k) != EOF) {
    double num = ceil((double)(n - k) / (double)k);
    double tmp =
        ((double)v1 * num +
         num * (double)v1 * (double)(v2 - v1) / (double)(v1 + v2) + (double)v2);
    double t2 = (double)l / tmp;
    double t1 = (double)(l - t2 * (double)v2) / (double)v1;
    printf("%.8f\n", t1 + t2);
  }
  return 0;
}
