counter = 0
for month in range(1, 13):
    if month == 1 or month == 3 or month == 5 or month == 7 or month == 8 or month == 10 or month == 12:
        for day in range(1, 32):
            if month == (day // 10) + (day % 10):
                counter += 1
    elif month == 4 or month == 6 or month == 9 or month == 11:
        for day in range(1, 31):
            if month == (day // 10) + (day % 10):
                counter += 1
    else:
        for day in range(1, 29):
            if month == (day // 10) + (day % 10):
                counter += 1

print(counter)