#include <stdio.h>

int main() {
   /*int a,b,c,d;
   scanf("%d %d %d %d",&a,&b,&c,&d);
   int MAX =(a>b)?a:b;
   MAX = (MAX > c)?MAX:c;
   MAX = (MAX > d)?MAX:d;
   printf("%d",MAX);*/
   int arr[4];
   int i =0;
   while(i<4){
   scanf("%d",&arr[i]);
   i++;
   }
   int n =1;
   int MAX = arr[0];
   while(n<4){
    if(arr[n]>MAX)
    MAX = arr[n];
    n++;
   }
   printf("%d",MAX);
    return 0;
}