#include <stdio.h>
int main()
{
    int n1, n2, n3, n4;
  	//用数组来保存四个科目的成绩
    scanf("%d %d %d %d", &n1, &n2, &n3, &n4);
    int score[4] = {n1,n2,n3,n4};
  	//假定第一个元素为最大值
    int max = score[0];
    int i = 0;
    for(i = 1; i < 4; i ++)
    {
      //逐个比较
       if(score[i] > max)
       {
           max = score[i];
       }
    }
    printf("%d\n", max);
    return 0;
}