#include <iostream>
#include <string>
using namespace std;
int main(int argc, char* argv[])
{
	string S="1234567891011121314151617123456789101112131415161712345678910111213141516171234567891011121314151617";
	int D;
	cin>>D;
	cout<<S[D-1]<<endl;
	return 0;
}