#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int n, l, v1, v2, k;
  while (scanf("%d %d %d %d %d", &n, &l, &v1, &v2, &k) != EOF) {
    double s1, p1, t;
    int h = (n + k - 1) / k;
    p1 = l / ((h - (h - 1) * 1.0 * (v2 - v1) / (v2 + v1)));
    s1 = p1 * (h + (h - 1) * 1.0 * (v2 - v1) / (v2 + v1));
    t = s1 / v2;
    printf("%.12lf\n", t);
  }
  return 0;
}
