import java.io.; import java.util.; public class Main{ public static void main(String[] args)throws Exception{ BufferedReader reader=new BufferedReader(new InputStreamReader(System.in)); String str; while((str=reader.readLine())!=null){ int max=0; char[] arr=str.toCharArray(); for(int i=1;i<arr.length;i++){ int left=i-1; int right=i; while(left>=0&&right<arr.length&&arr[left]==arr[right] ){ if(right-left+1>max){ max=right-left+1; } left--; right++; }

             }
            for(int i=1;i<arr.length;i++){ 
           int left=i-1;
           int right=i+1;
            while(left>=0&&right<arr.length&&arr[left]==arr[right] ){
                if(right-left+1>max){
                    max=right-left+1;
                }
                left--;
                right++;
            }
        }
        System.out.println(max);
    }
    
}

}