#include <bits/stdc++.h>
using namespace std;

#define BIT(x) (1ull << (x))
#define FOR(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
#define REP(i, n) FOR(i, 0, n)
#define RFOR(i, a, b) for (int i = (int)(b) - 1; i >= (int)(a); i--)
#define RREP(i, n) RFOR(i, 0, n)
#define EACH(i, v) for (__typeof((v).begin()) i = (v).begin(); i != (v).end(); ++i)
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
#define UNIQ(v) do {sort(ALL(v)); (v).erase(unique(ALL(v)), (v).end());} while (0)
#define PB push_back
#define MP make_pair
#define SIZE(v) ((int)(v).size())
#define DEBUG(x) cout << #x << " = " << x << endl


int dp[51][51];
string s;

int main()
{
	cin >> s;
	int res = 1;
	FOR(w, 2, SIZE(s)){
		REP(i, SIZE(s) - w + 1){
			bool f = true;
			REP(j, w){
				if (s[i + j] != s[i + w - 1 - j]){
					f = false;
					break;
				}
			}
			if (f) res = w;
		}
	}
	printf("%d\n", res);
}