itll be fun

#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <cmath>
#include <set>
#include <stack>
#include <bitset>
#include <map>

#ifndef M_PI
#define M_PI 3.141592653589
#endif
//#define int long long
#define double long double
#define f(variable, start, end) for (int variable = start; variable < end; ++variable)
#define be(a) a.begin(), a.end()
#define no cout << "NO\n"
#define yes cout << "YES\n"
#define nor cout << "NO\n"; return
#define yesr cout << "YES\n"; return
#define vi vector<int>
#define vvi vector<vector<int>>


using namespace std;


template<typename T, typename E>
vector<T> &operator>>(vector<T> &v, E a) {
    v.push_back(a);
    return v;
}

//abs for any type
template<typename T>
T abs(T a) {
    if (0 < a) {
        return a;
    } else {
        return -a;
    }
}

//pair output
template<typename E>
ostream &operator<<(ostream &os, pair<E, E> &t) {
    os << t.first << ' ' << t.second << '\n';
    return os;
}

//"map" pair output
template<typename E>
ostream &operator<<(ostream &os, pair<const E, E> &t) {
    os << t.first << ' ' << t.second << '\n';
    return os;
}

//vector output
template<typename T>
ostream &operator<<(ostream &os, vector<T> &vec) {
    for (T i : vec) {
        os << i << '\n';
    }
    cout << '\n';
    return os;
}

//2 dimensional vector output
template<typename T>
ostream &operator<<(ostream &os, vector<vector<T> > &vec) {
    for (vector<T> i : vec) {
        os << i;
    }
    return os;
}

struct Point {
    double x, y;

    Point() {
        x = 0;
        y = 0;
    }

    double dist(Point a) const {
        return sqrt((a.x - x) * (a.x - x) + (a.y - y) * (a.y - y));
    }

};

bool eq(double a, double b) {
    return fabs(a - b) <= 1e-7;
}

bool ge(double a, double b) {
    return a > b && !eq(a, b);
}

struct Vector {
    double x, y;

    Vector(Point A, Point B) {
        x = B.x - A.x;
        y = B.y - A.y;
    }

    double len() const {
        return sqrt(x * x + y * y);
    }

    double dot_product (Vector a) const {
        return x * a.x + y * a.y;
    }

    double cross_product (Vector a) const {
        return x * a.y - y * a.x;
    }
};

istream &operator>>(istream &in, Point &P) {
    in >> P.x >> P.y;
    return in;
}

ostream &operator<<(ostream &out, Point &P) {
    out << P.x << " " << P.y;
    return out;
}


int32_t main() {
    cin.tie(NULL);
    cout.tie(NULL);
    cout.setf(ios::fixed);
    cout.precision(10);
    ios_base::sync_with_stdio(false);

    Point P, A, B;
    cin >> P >> A >> B;
    Vector AB(A, B);
    Vector BA(B, A);
    Vector AP(A, P);
    Vector BP(B, P);
    if (ge(AB.dot_product(AP), 0) && ge(BA.dot_product(BP), 0))
        cout << fabs(AB.cross_product(AP)) / AB.len() << endl;
    else
        cout << min(P.dist(A), P.dist(B)) << endl;

    return 0;
}