#include<fstream>
#include<iostream>
#include<string.h>
using namespace std;
long i,m,act,j;
char T[505];
int main()
{
    ifstream in("palm.in");
    ofstream out("palm.out");
    in>>T;
    for ( i=0; i<strlen(T); ++i)
    {
        //cout<<"i) "<<i<<"\n";
        act=0;
        for ( j=0; i-j>=0 && i+j<strlen(T); ++j )
            if (( (T[i+j]==T[i-j]) && (T[i+j]-'a'<=T[i+j-1]-'a') && ( T[i-j]-'a'<=T[i-j+1]-'a')) || j==0 )
            {
               act++;
               //cout<<T[i+j]<<" "<<T[i-j]<<"@"<<j<<"\n";
            }
            else
                break;
        //cout<<act*2-1<<" ";
        if (act*2-1 > m)
            m=act*2-1;
       /* act=0;
        for ( j=0; i-j>0 && i+j<strlen(T); ++j )
            if (T[i+j]==T[i-j-1] && T[i+j]-'a'<=T[i+j-1]-'a' && T[i-j-1]-'a'<=T[i-j]-'a')
                act++;
            else
                break;
        //cout<<act*2<<"\n";
        if (act*2 > m)
            m=act*2;*/
    }
    out<<m<<"\n";

    return 0;
}