#include <iostream>
#include <string>
using namespace std;
int main(int argc, char* argv[])
{
	string S="12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455";
	int D;
	cin>>D;
	cout<<S[D-1]<<endl;
	return 0;
}