#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, l, v1, v2, k;
  cin >> n >> l >> v1 >> v2 >> k;
  int u = (n + k - 1) / k;
  double low = 0, high = l;
  for (int c = 0; c < 200; c++) {
    double mid = (low + high) / 2;
    if (u * mid / (v2 - v1) + ((u - 1) * mid / (v2 + v1)) - (l - mid) / v1 > 0)
      high = mid;
    else
      low = mid;
  }
  cout << fixed << setprecision(20) << (l - low) / v1 << endl;
}
