# include<iostream> # include<cstring> # include<cstring> using namespace std; int main(){ string s; getline(cin,s); int ss=s.size(),t=0,max=0,i,j; for (i=0;i<ss;i++){ t=0; for (j=ss-1;j>i;j--){ if (s[j]==s[i+t] && i+t<j){ t++; } else{ t=0; continue; } if (i+t==j-1 && 2*t+1>max) max=2*t+1; else if (i+t==j && 2*t>max) max=2*t; } } cout<<max<<endl; return 0; }