#include<stdio.h>
int main()
{
	int n1[4] = { 0 }; 
	int max = 0;   
	for (int i = 0; i < 4; i++)
	{
		scanf("%d", &n1[i]);	
	} 
	for (int j = 0; j < 4; j++)
	{
		if (n1[j] > max)
			max = n1[j]; 
			 
	}
	printf("%d",max); 
	return 0; 
}