#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define N 400001
#define M 262144

int n, k;
char s[N + 1];
int sa[N + 1], ra[N + 1], ha[N + 1], tmp[N + 1];
int sg[M * 2];

int min(int x, int y) {
    return x < y ? x : y;
}

int max(int x, int y) {
    return x > y ? x : y;
}

int cmp(const void *i_, const void *j_) {
    int i = *(int *)i_;
    int j = *(int *)j_;
    if (ra[i] != ra[j]) return ra[i] - ra[j];
    int ri = i + k <= n ? ra[i + k] : -1;
    int rj = j + k <= n ? ra[j + k] : -1;
    return ri - rj;
}

void buildsa() {
    for (int i = 0; i <= n; i++) {
	ra[i] = s[i];
	sa[i] = i;
    }
    k = 1;
    for (; k <= n; k *= 2) {
	qsort(sa, n + 1, sizeof(int), cmp);
	tmp[sa[0]] = 0;
	for (int i = 0; i < n; i++) {
	    tmp[sa[i + 1]] = tmp[sa[i]] + (cmp(&sa[i], &sa[i + 1]) < 0);
	}
	memcpy(ra, tmp, sizeof(ra));
    }
}

int buildha() {
    int k = 0;
    for (int i = 0; i <= n; i++) {
	if (ra[i] == n) continue;
	int j = sa[ra[i] + 1];
	while (s[i + k] == s[j + k]) k++;
	ha[ra[i]] = k;
	if (k > 0) k--;
    }
    for (int i = 0; i <= n; i++) {
	sg[i + M] = ha[i];
    }
    for (int i = M - 1; i > 0; i--) {
	sg[i] = min(sg[i * 2], sg[i * 2 + 1]);
    }
}

int lcp(int i, int j) {
    if (i == j) return n - i;
    i = ra[i];
    j = ra[j];
    int l = min(i, j) + M;
    int r = max(i, j) + M;
    int res = 2147483647;
    for (; l < r; l >>= 1, r >>= 1) {
	if (l & 1) res = min(res, sg[l++]);
	if (r & 1) res = min(res, sg[--r]);
    }
    return res;
}

int solve(int i, int j, int n1, int n2) {
    int h = lcp(i, j);
    if (h == n1 || h == n2) return h;
    i += h;
    j += h;
    return h + max(lcp(i + 1, j), lcp(i, j + 1));
}

int main() {
    scanf("%s", s);
    int m = strlen(s);
    for (int i = 0; i < m; i++) {
	s[m + 1 + i] = s[m - 1 - i];
    }
    s[m] = '$';
    n = m * 2 + 1;
    s[n] = 0;
    buildsa();
    buildha();
    int ans = 0;
    /* even length */
    for (int i = 0; i < m; i++) {
	int x = 2 * solve(i + 1, n - i, m - i - 1, i);
	x = min(x, m - 2);
	ans = max(ans, x + 1);
    }
    /* odd length */
    for (int i = 1; i < m; i++) {
	int x = 2 * solve(i, n - i, m - i, i);
	x = min(x, m - 1);
	ans = max(ans, x);
    }
    printf("%d\n", ans);
    return 0;
}