#include <iostream>
#include <cmath>
#include <fstream>
using namespace std;
int main()
{
    freopen ( "digits.in", "r", stdin );
	freopen ( "digits.out", "w" , stdout );
    long long n=0,k,a=0,i=2,j=0,b;
    double p;
    cin>>k;
    do
    {
        p=pow((double)i,(double)j);
        a=(long long) p;
        j++;
        b=a;
        while (b>0)
        {
            b/=10; n++;
        }
    }
    while (k>n); i=10;
    p=pow((double)i,(double)(n-k));
    j=(long long) p;
    cout<<a/j%10<<endl;
    return 0;
}