#include <bits/stdc++.h>

using ll = long long;
using namespace std;
const int INFint = 1e9+1;
const ll INFll = (ll)1e18+1;
ll MOD=1e9+7;


int main(){
  int a,b,c,d,e,f;
  cin>>a>>b>>c>>d>>e>>f;
  double l,m,n;
  l = c/(double)a;
  m = d/(double)a;
  n = (e-f)/(double)a;
  cout << setprecision(10) << sqrt(l*l+m*m-4*n)/2 << endl;
  return 0;
}