#include<iostream> #include<cstring> using namespace std; char a[1001]; int main(){ int k; cin>>k>>a; int count=1; bool exist=0; if(k==1){ cout<<a[0]; }else{ for(int i=1;i<int(strlen(a));i++){ if(a[i]==a[i-1]){ count++; if(count==k){ cout<<a[i]; exist = 1; break; } } } }if(exist == 0){ cout<<"No"; }return 0; }