#include <cstdio>
#include <algorithm>
#include <cstring>
#include <cstdlib>

using namespace std;

//namaega184 

int main(){
	char s[51];scanf("%s",s);
	int len=strlen(s),ans=1; 
	int cnt=0;
	for(int i=0;i<len;i++){
		for(int j=i+1;j<len;j++){
			bool f=1;
			for(int a=i,b=j;a<b;a++,b--){
				if(s[a]!=s[b]){f=0;break;}
			}
			if(f){if(j+1-i!=len&&j+1-i>ans)ans=j-i+1;}
		}
	}
	printf("%d\n",ans);
	return 0;
}