#include<stdio.h>
int main(void){
	int month[12] = {31,28,31,30,31,30,31,31,30,31,30,31};
    int sum = 0,m_month = 0;
    int td,d;
    
    for (int i = 1; i <= 12; i++) {
        m_month = month[i];
        for (int j = 1; j <= m_month; i++) {
            td = j / 10;
            d = j % 10;
            
            if ((td + d) == i) {
                sum ++;
            }
            
        }
        
    }
    
    printf("%d\n",sum);
    
    return 0;
}