#include <bits/stdc++.h>
int main() {
  int n, l, v1, v2, k;
  while (~scanf("%d%d%d%d%d", &n, &l, &v1, &v2, &k)) {
    int cnt = n / k + (bool)(n % k);
    double tmp = 1.0 * (v2 - v1) / (v1 + v2) * (cnt - 1) + cnt - 1;
    double ans = 1.0 * l * (tmp + 1) / (v1 * tmp + v2);
    printf("%.9lf\n", ans);
  }
}
