#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)

int main()
{
	string S; cin >> S;
	int ans = 1;
	rep(i, 0, S.length()) rep(j, i, S.length())
	{
		if (i == 0 && j == S.length() - 1) continue;
		bool ok = true;
		rep(k, 0, (j - i + 1) / 2)
		{
			if (S[i + k] != S[j - k]) ok = false;
		}
		if (ok) ans = max(ans, j - i + 1);
	}
	cout << ans << endl;
}