#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;
ifstream in("palm.in");
ofstream out("palm.out");
char s[510];
int lmax,n,l,start,finish;
int main()
{
in>>s;
in.get();
n=strlen(s);
for(int i=0;i<n;++i)
{
l=1;
while(i-l>=0 && i+l<n && s[i-l]==s[i+l] && s[i-l]<=s[i-l+1] && s[i+l-1]>=s[i+l])
++l;
if(lmax<2*l-1){
lmax=2*l-1;
start=i-l+1;
finish=i+l-1;
}
l=1;
while(i-l>=0 && i+l<n && s[i-l]==s[i+l] && s[i-l]>=s[i-l+1] && s[i+l-1]<=s[i+l])
++l;
if(lmax<2*l-1){
lmax=2*l-1;
start=i-l+1;
finish=i+l-1;
}
l=0;
while(i-l>+0 && i+l<n && s[i-l]==s[i+l+1] && s[i-l]<=s[i-l+1] && s[i+l]>=s[i+l+1])
++l;
if(lmax<2*l){
lmax=2*l;
start=i-l+1;
finish=i+l;
}
l=0;
while(i-l>+0 && i+l<n && s[i-l]==s[i+l+1] && s[i-l]>=s[i-l+1] && s[i+l]<=s[i+l+1])
++l;
if(lmax<2*l){
lmax=2*l;
start=i-l+1;
finish=i+l;
}
}
out<<lmax;
return 0;
}