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

#define N 400001
#define M 262144

int n;
char s[N+1];
int sa[N+1], ra[N+1], ha[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; }

void buildsa() {
    for (int i = 0; i <= n; i++) ra[i] = s[i];
    for (int k = 1; k <= n; k *= 2) {
        static int rb[N + 1], sm[N + 3], tm[N + 1];
        for (int i = 0; i <= n; i++) rb[i] = i + k <= n ? ra[i + k] + 1 : 0;
        memset(sm, 0, sizeof(sm));
        for (int i = 0; i <= n; i++) sm[rb[i] + 1]++;
        for (int i = 0; i <= N; i++) sm[i + 1] += sm[i];
        for (int i = 0; i <= n; i++) sa[sm[rb[i]]++] = i;
        memset(sm, 0, sizeof(sm));
        memcpy(tm, sa, sizeof(tm));
        for (int i = 0; i <= n; i++) sm[ra[i] + 1]++;
        for (int i = 0; i <= N; i++) sm[i + 1] += sm[i];
        for (int i = 0; i <= n; i++) sa[sm[ra[tm[i]]]++] = tm[i];
        tm[sa[0]] = 0;
        for (int i = 1; i <= n; i++) tm[sa[i]] = tm[sa[i - 1]] + (ra[sa[i - 1]] != ra[sa[i]] || rb[sa[i - 1]] != rb[sa[i]]);
        memcpy(ra, tm, sizeof(ra));
    }
}

void 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;
}