#include <bits/stdc++.h>
using namespace std;
double n, l, v1, v2, k, low, high, g, dis, ans, mid;
int main() {
  cin >> n >> l >> v1 >> v2 >> k;
  g = ceil(n / k);
  low = 0;
  high = l;
  while (low < high) {
    mid = (low + high) / 2;
    dis = v2 * mid + (g - 1) * (mid * 2 * v1 * v2) / (v1 + v2);
    if (abs(dis - l) <= 0.00000000001) break;
    if (dis > l) {
      high = mid - 0.00000000001;
    } else if (dis < l) {
      low = mid + 0.00000000001;
    }
  }
  ans = g * mid + (g - 1) * (v2 - v1) * mid / (v2 + v1);
  printf("%0.10lf", ans);
  return 0;
}
