#include <bits/stdc++.h>
using namespace std;
const int inf = 0x3f3f3f3f;
const long long INF = 2e18;
const int N = 1231234;
int n, L, v1, v2, m;
bool ok(double x) {
  double l = 0, r = 1e9;
  for (int i = 0; i < 88; ++i) {
    double m = (l + r) / 2;
    if (v2 * m + v1 * (x - m) >= L)
      r = m;
    else
      l = m;
  }
  if (v1 * l + v2 * (x - l) < L) return false;
  double len = l * (v2 - v1);
  double t = l + len / (v2 + v1);
  int cishu = (n + m - 1) / m;
  return cishu * t - len / (v1 + v2) <= x;
}
int main() {
  while (cin >> n >> L >> v1 >> v2 >> m) {
    int i, j;
    double ans = 0;
    if (m >= n)
      printf("%.9f\n", L * 1.0 / v2);
    else {
      double l = 0, r = 1e9;
      for (i = 0; i < 88; ++i) {
        double mid = (l + r) / 2;
        if (ok(mid))
          r = mid;
        else
          l = mid;
      }
      printf("%.9f\n", (l + r) / 2);
    }
  }
}
