#include <bits/stdc++.h>
using namespace std;
double n, l, v1, v2, k;
int main() {
  while (cin >> n >> l >> v1 >> v2 >> k) {
    double t2;
    long long int w = (long long int)(n) / (long long)k +
                      ((long long)n % (long long)k == 0 ? 0 : 1);
    double zuo = 1.0 * (v1 + v2) * l;
    t2 = zuo / (v1 * v2 * 1.0 + v2 * v2 + 2 * v1 * v2 * (w - 1) * 1.0);
    double t1 = (t2 * v2 - t2 * v1) / (1.0 * (v1 + v2));
    printf("%.10lf\n", t2 * w * 1.0 + (w - 1) * t1);
  }
  return 0;
}
