public class Main{
	int[] L;
	int N;
	long K;

	public static void main(String[] args) {
		Main main=new Main();
		main.run();
	}

	void run() {

		int[] date= {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

		int res=0;
		for(int i=0;i<12;i++) {
			for(int j=1;j<=date[i];j++) {

				if(i==(j/10+j%10)) {
					res++;
				}

			}
		}

		System.out.println(res);
	}

}