#include <bits/stdc++.h>
using namespace std;
int n, L, v1, v2, K;
double inf, sup, mid, ans;
bool Check(double y) {
  double x = L - y;
  double Time = x * 1.0 / v1 + y * 1.0 / v2;
  return K * y * 1.0 / v2 +
             (K - 1) * y * 1.0 / (v1 + v2) * (1 - v1 * 1.0 / v2) <=
         Time;
}
int main() {
  cin >> n >> L >> v1 >> v2 >> K;
  K = (n - 1) / K + 1;
  inf = 0;
  sup = L;
  for (int i = 1; i < 100; i++) {
    mid = (inf + sup) / 2;
    if (Check(mid)) {
      ans = mid;
      inf = mid;
    } else
      sup = mid;
  }
  ans = ans * 1.0 / v2 + (L - ans) * 1.0 / v1;
  cout << fixed << setprecision(10) << ans << endl;
}
