#include <stdio.h>

int main(void){
	int ans = 0;
	int i,j;
	int day[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
	
	
	for(i=1;i<=12;i++){
		for(j=1;j<=day[i];j++){
			int a,b;
			a = j/10;
			b = j%10;
			if(i == (a+b)){
				ans++;
			}
		}
	}
	
	printf("%d\n", ans);
	return 0;
}