#include <bits/stdc++.h>
using namespace std;
template <typename T>
void read(T &x) {
  x = 0;
  char ch = getchar();
  int fh = 1;
  while (ch < '0' || ch > '9') {
    if (ch == '-') fh = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar();
  x *= fh;
}
template <typename T>
void write(T x) {
  if (x < 0) x = -x, putchar('-');
  if (x > 9) write(x / 10);
  putchar(x % 10 + '0');
}
template <typename T>
void writeln(T x) {
  write(x);
  puts("");
}
int n, l, v1, v2, k;
signed main() {
  cin >> n >> l >> v1 >> v2 >> k;
  int m = n / k;
  if (n % k != 0) m++;
  double tm = (double)v2 / (double)v1;
  double big = (tm + 1.0) / 2.0, small = (tm - 1.0) / 2.0;
  double tot = big + (double)(m - 1.0);
  double sum = (double)m * big + (double)(m - 1) * small;
  double s = (double)l / tot * sum;
  cout << fixed << setprecision(10) << s / (double)v2 << endl;
  return 0;
}
