public class Sample01 {

	public static void main(String[] args) {
		int[] lastDay = new int[]{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
		int cnt = 0;

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

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

		System.out.println(cnt);
	}

}