#include <stdio.h>int max(int x,int y);void main(){ int a[4],i; for(i=0;i<4;i++) { scanf("%d",&a[i]); } i=0; printf("%d\n",max(max(a[i],a[i+1]),max(a[i+2],a[i+3])));}int max(int x,int y){ return x>y?x:y;}