month_30 = [
    4,
    6,
    9,
    11
]

month_28 = [
    2
]
cnt = 0
for month in range(1, 13):
    if month in month_30:
        days = 30
    elif month in month_28:
        days = 28
    else:
        days = 31
    
    for day in range(1, days+1):
        if month == day//10 + day%10:
            cnt += 1

print(cnt)