# include<iostream> # include<cmath> using namespace std; int main() { int x1,y1,x2,y2,a,b; cin>>x1>>y1>>x2>>y2; a=x2-x1; b=y2-y1; if(abs(a)>abs(b)){ cout<<abs(a); } else{ cout<<abs(b); } return 0; }