day = [31,28,31,30,31,30,31,31,30,31,30,31]
result = 0
x = 0
y = 0
for month in range(12):
    for n in range(1,day[month]+1):
        if n >= 10:
            x = int(n / 10)
            y = n - x*10
            if month + 1 == x + y:
                result += 1
        else:
            if n == month+1:
                result += 1
        x=0
        y=0
print(result)