#include <stdio.h>

int main()
{
    int cnt = 0;
    for (int i = 1;i <= 12;i++) {
        int days = 0;
        switch (i) {
        case 1:
            days = 31;
            break;
        case 2:
            days = 28;
            break;
        case 3:
            days = 31;
            break;
        case 4:
            days = 30;
            break;
        case 5:
            days = 31;
            break;
        case 6:
            days = 30;
            break;
        case 7:
            days = 31;
            break;
        case 8:
            days = 31;
            break;
        case 9:
            days = 30;
            break;
        case 10:
            days = 31;
            break;
        case 11:
            days = 30;
            break;
        case 12:
            days = 31;
            break;
        }
        for (int j = 0;j <= days;j++) {
            if (i == j/10 + j%10) {
                cnt++;
            }
        }
    }
    printf("%d\n",cnt);
}