#include<stdio.h>
#include<string.h>
char a,b;
int k,m,max;
int main()
{
	FILE *f = fopen("palm.in","r");
	FILE *g = fopen("palm.out","w");
	a=fgetc(f);
	while(!feof(f))
	{
		b=fgetc(f);
			if(b==a+1)
				++k;
			else
				if((b==a-1)&&(m<=k))
				{
					m++;
				}
				else
				{	if(m>k)
					{	m=0;
						k=2*k+1;
						if(max<k)
							max=k;
						k=0;
					}
					else
					{
						m=0;
						k=2*k+1;
						if(max<k)
							max=k;
						k=0;
					}
				}
		a=b;
	}
	fprintf(g,"%d",max);
	fclose(f);
	fclose(g);
	return 0;
}