#include <bits/stdc++.h>
using namespace std;
int read() {
  int s = 0, fh = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') fh = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    s = s * 10 + (ch - '0');
    ch = getchar();
  }
  return s * fh;
}
int main() {
  double n, l, v1, v2, k, a, b, c, d;
  long long K;
  scanf("%lf %lf %lf %lf %lf", &n, &l, &v1, &v2, &k);
  K = ((long long)n + (long long)k - 1LL) / (long long)k;
  a = (K * l) / (v2 - v1);
  b = (l * ((double)K - 1.0)) / (v1 + v2);
  c = (K * v1) / (v2 - v1);
  d = ((K - 1.0) * v1) / (v1 + v2);
  printf("%.10lf", (a + b) / (1.0 + c + d));
  return 0;
}
