#include<cstdio>
#include<cstring>
void read(),solve();
char A[510];
int len,i,st,dr,sol;
int main()
{
	read();
	solve();
	return 0;
}
void read()
{
	freopen("palm.in","r",stdin);
	freopen("palm.out","w",stdout);
	scanf("%s",A+1);
}
void solve()
{
	len=strlen(A+1);
	for(i=2;i<len;i++)
	{
		for(st=i-1,dr=i+1;st>=1&&dr<=len;st--,dr++)
			if(!(A[st]==A[dr]&&A[st]<=A[st+1]&&A[dr]<=A[dr-1])){st++;dr--;break;}
		if(sol<dr-st+1)sol=dr-st+1;
	}
	printf("%d\n",sol);
}