#include<stdio.h>

int main(void){
	int m,d,c = 0,t[16]={0,31,28,31,30,31,30,31,31,30,31,30,31};
	for(m = 1;m <= 12;m++){
		for(d = 1;d <= t[m];d++){
			if(m == d/10 + d%10){c++;}
		}
	}
	printf("%d\n",c);
	return 0;
}