num = 0
day = []
for i in xrange(1,31):
    s = str(i)
    for j in s:
        num += int(j)
    day.append(num)
    num = 0
month = [i for i in xrange(1,13)]
ans = 0
for i in month:
    for j in day:
        if i == j:
            ans += 1
print ans