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