# include<iostream> # include<string> # include<algorithm> using namespace std; bool hw(string s1){ string s2=s1; reverse(s2.begin(),s2.end()); for(int i=0;i<=s1.size();i++){ s2[i]=s1[s1.size()-1-i]; // s1="abcddaa" // s2="" } if(s2!=s1) return 0; return 1; } int main(){ string s1,s2; int longest=0; getline(cin,s1); for(int i=0;i<s1.size();i++){// s2=""; for(int j=i;j<s1.size();j++){ s2=s2+s1[j]; //cout<<s2<<endl; if(hw(s2)==1&&s2.size()>longest) longest=s2.size(); } } cout<<longest<<endl; return 0; }