#include <bits/stdc++.h>
using namespace std;
const long double PI = acos(-1);
int d1[4][2] = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};
int d2[8][2] = {{1, 0}, {0, 1},  {0, -1}, {-1, 0},
                {1, 1}, {-1, 1}, {1, -1}, {-1, -1}};
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  double n, l, v1, v2, k;
  cin >> n >> l >> v1 >> v2 >> k;
  double L = 0, R = 10000000000;
  int it = 200;
  while (it--) {
    double mid = (L + R) / 2;
    double w = true;
    int cnt = (n + k - 1) / k;
    double x = l;
    double T = mid;
    for (int i = 0; i < cnt; ++i) {
      double y = (T * v1 * v2 - v2 * x) / (v1 - v2);
      if (y > x) w = false;
      T -= y / v2;
      if (i != (cnt - 1)) T -= (y - v1 * y / v2) / (v2 + v1);
      if (T < 0) w = false;
      x -= v1 * y / v2 + v1 * (y - v1 * y / v2) / (v2 + v1);
      if (x < 0) w = false;
    }
    if (!w)
      L = mid;
    else
      R = mid;
  }
  cout << fixed << setprecision(10) << L << "\n";
  return 0;
}
