#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1000000007;
const double PI = acos(-1.);
const double eps = 1e-9;
long long modPow(long long a, long long b, long long MOD) {
  long long ret = 1;
  for (; b; b >>= 1) {
    if (b & 1) ret = ret * a % MOD;
    a = a * a % MOD;
  }
  return ret;
}
void solve() {
  int n, l, p, q, k;
  scanf("%d%d%d%d%d", &n, &l, &p, &q, &k);
  double le = 0, re = 1. * l / p;
  for (int i = (0); i < (int)(1000); i++) {
    double me = (le + re) / 2;
    int m = n;
    double d = l;
    double t = 0;
    int fail = 0;
    while (m) {
      if (t > me) {
        fail = 1;
        break;
      }
      double dt = (d - p * (me - t)) / (q - p);
      t += dt;
      d -= dt * p;
      m = max(0, m - k);
      if (t > me) {
        fail = 1;
        break;
      }
      if (m) {
        dt = dt * (q - p) / (p + q);
        t += dt;
        d -= dt * p;
      }
    }
    if (fail)
      le = me;
    else
      re = me;
  }
  printf("%.16f\n", (le + re) / 2);
}
int main() {
  int _T = 1;
  for (int CA = (0); CA < (int)(_T); CA++) {
    solve();
  }
  return 0;
}
