package _test;

import java.util.Scanner;

public class No756 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int D = sc.nextInt();
		int length = 0;
		int ans = 0;
		for (int i = 1; i <= 100; i++) {
			if (i < 10)
				length += 1;
			else if (i < 100)
				length += 2;
			else
				length += 3;

			if (length >= D) {
				if (length == D) {
					ans = i % 10;
				} else {
					if (i < 100) {
						ans = i % 10;
					} else {
						ans = i % 100;
					}
				}
				break;
			}
		}
		System.out.println(ans);
	}
}