#include<iostream> #include<cstdio> //scanf()\printf() #include<cstring> #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ char a[2501]; int s1,k,sum=1; cin>>k>>a; s1=strlen(a); for(int i=0;i<s1-1;i++){ if(k==sum){ cout<<a[i]; return 0; } else{ if(a[i]==a[i+1]) sum++; else sum=1; } } cout<<"No"; return 0; }