#include <iostream>
#include <cmath>
using namespace std;


float distance(float x1, float y1, float x2, float y2)
{
    return sqrt(pow(x2 - x1, 2) + pow(y2 - y1, 2));
}


int main()
{
    float a, b, x, y;

    cout << "Enter the first point" << endl;
    cin >> a >> b;

    cout << "Enter the second point" << endl;
    cin >> x >> y;

    float result = distance(a,b,x,y);


    cout << "The distance between those two points is " << result << endl;

    return 0;
}