# coding: utf-8
# Here your code !
array = []


i = 1
for i in range(32):
    a = int(i/10)
    if i < 10:
        b = i
    elif i < 20:
        b = i - 10
    elif i < 30:
        b = i - 20
    elif i < 40:
        b = i - 30
    
    for i in range(13):
        if a + b == i:
            array.append("happy day")
        
print(len(array))