#include<stdio.h>
int main(void){
	int i,j,cnt=0,lday[]={0,31,28,31,30,31,30,31,31,30,31,30,31};

	for(i=1;i<=12;i++){
		for(j=1;j<=lday[i];j++){
			if(j/10 + j-j/10*10 == i) cnt++;
		}
	}

	printf("%d\n",cnt);

	return 0;
}