#include #define FOR(i,a,b) for(int i = (a); i < (b); ++i) #define REP(i,n) FOR(i,0,n) #define RREP(i,n) for(int i = (n) - 1; (i) >= 0; --i) #define SZ(n) (int)(n).size() #define ALL(n) (n).begin(), (n).end() #define MOD LL(1e9 + 7) #define INF 1000000 using namespace std; typedef long long LL; typedef vector VI; typedef pair PI; int main() { string s; cin >> s; int sz = s.size(); int ans = 0; REP(i, sz) { FOR(j, i + 1, sz + 1) { string ns = s.substr(i, j - i); string t = ns; reverse(ALL(ns)); if (t == ns) ans = max(ans, j - i); } } cout << ans << endl; return 0; }