#include <bits/stdc++.h>
using namespace std;
long long n, l, k, v1, v2;
bool chk(long double X) {
  long double curr = 0;
  long double nn = l;
  long double f_time;
  long double x = X;
  for (long long i = 1; i < (n + k - 1) / k; i++) {
    long double diss = nn - curr;
    long double y = ((x * (long double)v1 * (long double)v2) -
                     (l * (long double)v2) + (curr * (long double)v2)) /
                    (long double)((long double)v1 - (long double)v2);
    long double time = y / (long double)v2;
    y += curr;
    curr += (time * v1);
    long double xx = ((y - curr) * (long double)v1) / (long double)(v1 + v2);
    curr += xx;
    f_time = (curr / (long double)v1);
    x = X - f_time;
  }
  x -= ((l - curr) / (long double)v2);
  return (x >= 0);
}
void query() {
  cin >> n >> l >> v1 >> v2 >> k;
  long double L = 0.0, R = l * (long double)v1, ans = R, diff = 1e-6;
  while ((R - L) >= 1e-6) {
    long double mid = (L + R) / 2.0;
    if (chk(mid)) {
      R = mid;
      ans = min(ans, mid);
    } else {
      L = mid;
    }
  }
  cout << setprecision(15) << ans << "\n";
}
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  long long t = 1;
  while (t--) {
    query();
  }
}
