public class No0188 {
	public static void main(String[] args) {
		int end[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
		int cnt = 0;
		for(int m=1; m<=12; m++){
			for(int d=1; d<=end[m-1]; d++){
				if(m == (d/10 + d%10)){
					cnt++;
				}
			}
		}
		System.out.println(cnt);
	}
}