#include <iostream> using namespace std; int main(){ int x1,y1, x2,y2; cin>>x1>>y1>>x2>>y2; int x12 = x1-x2; // 正，负 if (x12<0) x12 = x12*-1; int y12 = y1-y2; if( y12 <0) y12 = y12*-1; if (x12>y12) cout<<x12; else cout<< y12;//如果相等，在这里输出。 return 0; }