tj

#include<bits/stdc++.h>
using namespace std;
int a,b,c,d;
int main(){
cin >> a >> b >> c >> d;
int m1 = max(a,c);
int m2 = min(a,c);
int m3 = max(b,d);
int m4 = min(b,d);
cout << (m1 - m2) + (m3 - m4);

return 0;

}