#include<stdio.h>
#include<string.h>
FILE*f=fopen("palm.in","r");
FILE*g=fopen("palm.out","w");
char v[501];
int max;
int main() {
	fscanf(f,"%s",v+1);
	int n=strlen(v+1);
	for(int i=1;i<=n;++i){
		int j=1;
		int sol=1;
		while(v[i-j]==v[i+j]&&i+j<=n&&i-j>0&&v[i+j]<=v[i+j-1]){
			++j;
			sol+=2;
		}
		if(sol>max)
			max=sol;
	}
	
	for(int i=1;i<=n;++i){
		int j=1;
		int sol=0;
		while(v[i-j+1]==v[i+j]&&i+j<=n&&i-j+1>0&&v[i+j]<=v[i+j-1]){
			++j;
			sol+=2;
		}
		if(sol>max)
			max=sol;
	}
	
	fprintf(g,"%d",max);
	
	
	fclose(g);
	fclose(f);
	return 0;
}