#include "bits/stdc++.h"
using namespace std;
#define ll long long int
#define rep(i,n) for( int i = 0; i < n; i++ )
#define rrep(i,n) for( int i = n; i >= 0; i-- )
#define REP(i,s,t) for( int i = s; i <= t; i++ )
#define RREP(i,s,t) for( int i = s; i >= t; i-- )
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define INF 2000000000
#define mod 1000000007
#define INF2 1000000000000000000


int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);
	string S; cin >> S;
	int ans = 1;
	rep(i, S.length()) {
		int cnt = 1;
		for (int j = 1; i + j < S.length() && i - j >= 0; j++) {
			if (S[i + j] == S[i - j]) cnt += 2;
		}
		ans = max(ans, cnt);
		cnt = 0;
		for (int j = 0; i + j + 1 < S.length() && i - j >= 0; j++) {
			if (S[i + j + 1] == S[i - j]) cnt += 2;
		}
		ans = max(ans, cnt);
	}
	cout << ans << endl;


    return 0;
}