#include <bits/stdc++.h>
using namespace std;
int n, k, v1, v2, L;
bool can(double m) {
  double bus = 0, nbus = 0;
  for (int i = 0; i < (n + k - 1) / k; i++) {
    if (i == 0)
      bus += m * v2;
    else
      bus += m * v1;
    nbus += m * v1;
    if (bus > L) return false;
    double sb = (bus - nbus) / (v1 + v2);
    bus += sb * v1;
    nbus += sb * v1;
  }
  return true;
}
int main() {
  scanf("%d%d%d%d%d", &n, &L, &v1, &v2, &k);
  double l = 0, r = (double)L / v2, m;
  for (int i = 0; i < 100; i++) {
    m = (l + r) / 2.0;
    if (can(m))
      l = m;
    else
      r = m;
  }
  printf("%.12f", m + (L - m * v2) / v1);
}
