#include<iostream> #include<cstdlib> #include<cstdio> #include<cstring> #include<string> using namespace std; const int N=1e6+5; int n,ans,s1,s2,mi; char ch[N]; int main (){ scanf ("%d%s",&n,ch+1); ans=n;mi=1; for (int i=1;i<n;++i){ s1=s1*37+ch[i]; s2=ch[n-i+1]*mi+s2;mi*=37; if (s1==s2)ans=n-i; } printf ("%d\n",ans); return 0; }