public class No188 {
	public static void main(String[]args) {
		int [] d = new int[12];
		d[0]=31;
		d[1]=28;
		d[2]=31;
		d[3]=30;
		d[4]=31;
		d[5]=30;
		d[6]=31;
		d[7]=31;
		d[8]=30;
		d[9]=31;
		d[10]=30;
		d[11]=31;

		int counter=0;

		for(int i=0;i<12;i++) {
			for(int j=1;j<d[i]+1;j++) {
				int a,b;
				a=j/10;
				b=j%10;

				if(i==a+b) {
					counter++;
				}

			}
		}

		System.out.println(counter);

	}

}