#include <bits/stdc++.h>
using namespace std;
inline long long rd() {
  long long x = 0;
  int ch = getchar(), f = 1;
  while (!isdigit(ch) && (ch != '-') && (ch != EOF)) ch = getchar();
  if (ch == '-') {
    f = -1;
    ch = getchar();
  }
  while (isdigit(ch)) {
    x = (x << 1) + (x << 3) + ch - '0';
    ch = getchar();
  }
  return x * f;
}
inline void rt(long long x) {
  if (x < 0) putchar('-'), x = -x;
  if (x >= 10)
    rt(x / 10), putchar(x % 10 + '0');
  else
    putchar(x + '0');
}
int n, s;
long double len, v1, v2;
bool solve(long double ans) {
  double k = (len - v1 * ans) / (v2 - v1);
  if (ans - n * k - (n - 1) * (v2 - v1) * k / (v2 + v1) > 1e-7)
    return 1;
  else
    return 0;
}
int main() {
  n = rd(), len = rd(), v1 = rd(), v2 = rd(), s = rd();
  n = (n - 1) / s + 1;
  long double l = len / v2, r = len / v1;
  while (r - l > 1e-7) {
    long double mid = (l + r) / 2;
    if (solve(mid))
      r = mid;
    else
      l = mid;
  }
  printf("%.10lf\n", (double)l);
}
