#include<stdio.h>
#include<vector>


using namespace std;


vector < int> p [30];
char a[510];
int b[510],c[510],d[510];


int main()
{
	freopen("palm.in","r",stdin);
	freopen("palm.out","w",stdout);
	int max=0,i=0,j,lim,n,lim2,k;
	while(scanf("%c",&a[++i])!=EOF)
	{
		n=a[i]-'a';
		if(a[i]==a[i-1])
		{
			d[i]=d[i-1]+1;
			c[i]=c[i-1]+1;
			b[i]=b[i-1]+1;
		}
		if(a[i]<a[i-1])
		{
			b[i]=b[i-1]+1;
			++c[i];
		}
		if(a[i]>a[i-1])
		{
			c[i]=c[i-1]+1;
			++b[i];
		}
		if(!p[n].empty())
		{
			lim=p[n].size();
			for(j=0;j<lim;++j)
				if(i-p[n][j]!=1)
				{
				if(c[p[n][j]]-d[p[n][j]]==b[i-b[i]]-d[i-b[i]])
				{
					lim2=(1+i-p[n][j])/2;
					for(k=0;k<=lim2&&a[i-k]==a[p[n][j]+k];++k);
					if(k==lim2+1&&i-p[n][j]+1>max)
						max=i-p[n][j]+1;
				}
				}
				else
					if(a[i]==a[p[n][j]]&&max==0)
						max=2;
		}
		p[n].push_back(i);
	}
	if(!max)
		max=1;
	printf("%d\n",max);
	return 0;
}