#include <iostream>
//#include<atcoder/all>
#include <numeric>
#include <cmath>
#include <limits>
#include <stdio.h>
#include <iomanip>
#include <string> 
#include <vector>
#include <algorithm>
#include <utility> 
#include <tuple> 
#include <cstdint> 
#include <cstdio> 
#include <map> 
#include <queue>
#include <set> 
#include <stack> 
#include <deque> 
#include <unordered_map> 
#include <unordered_set>
#include <bitset> 
#include <cctype>
//using namespace atcoder;
using namespace std;
using ll = long long;
#define all(A) A.begin(),A.end()
using vll = vector<ll>;
#define rep(i, n) for (long long i = 0; i < (long long)(n); i++)
using Graph = vector<vector<pair<ll, ll>>>;
int main() {
	double A, B, C, D, E, F;
	cin >> A >> B >> C >> D >> E >> F;
	cout << setprecision(16);
	C /= A; D /= A; E /= A; F /= A;
	F -= E;
	F += (C / 2 * C / 2) + (D / 2 * D / 2);
	cout << sqrt(F) << endl;
}