#include<iostream>
#include<cmath>

using namespace std;

int main(){
    double x1,y1,x2,y2,result;

    cin >>x1>>y1>>x2>>y2;
    result = sqrt((x1-x2) * (x1-x2) + (y1-y2) * (y1-y2));

    cout <<"结果:"<<int(result)<<endl;
}