// A is for "Ant"

#include <stdio.h>

#define S_MAX 1000

char s[S_MAX + 1];

int max(int a, int b){
	return (a > b) ? a : b;
}

int odd(){
	char *first, *last;
	char *center;
	int answer = 0;
	for (center = s; *center; center++) {
		int maybe_ans = -1;
		first = last = center;
		while (first - s >= 0 && *last) {
			if (*first == *last)
				maybe_ans += 2;
			first--;
			last++;
		}
		if (maybe_ans > answer) {
			answer = maybe_ans;
		}
	}
	return answer;
}

int even(){
	char *first, *last;
	char *centeright;
	int answer = 0;
	for (centeright = s + 1; *centeright; centeright++) {
		int maybe_ans = 0;
		first = centeright - 1, last = centeright;
		while (first - s >= 0 && *last) {
			if (*first == *last)
				maybe_ans += 2;
			first--;
			last++;
		}
		if (maybe_ans > answer) {
			answer = maybe_ans;
		}
	}
	return answer;
}

int solve(){
	return max(even(), odd());
}

int main(void){
	scanf("%s", s);
	printf("%d\n", solve());
	return 0;
}