开荒

#include<bits/stdc++.h>
using namespace std;
string s;
unsigned long long len,n;
double q;
long long x;
int main(){
    cin>>s>>n;
    len=s.size();
    for(int i=len;i>=1;i--)s[i]=s[i-1];
    long long i=n;
    long long num=len;
   while(num*2<=n)num*=2;
   if(num!=n)num*=2;
   while(1) { 	
	    if(i<=len){
    		cout<<s[i];
    		return 0;
		}
    	if(i==num/2+1)i=num/2;
    	else if(i>(num/2))i=(i-1)-(num/2);
		num/=2;
   
	}
}