#include<fstream>
#include<cstdlib>
using namespace std;
char s[505];
int i,j,k,maxim,n;
int main()
{
	ifstream f("palm.in");ofstream g("palm.out");
	f.getline(s,501);
	n=strlen(s);
	for(i=0;i<n;i++)
	{
	  k=1;
	  for(j=1;j<=i+1 && s[i-j]==s[i+j] && s[i-j]<=s[i-j+1] && s[i+j]<=s[i+j-1];j++)
		  k+=2;
	  if(k>maxim)maxim=k;
	}
	g<<maxim;
	f.close();g.close();
return 0;}