import math
import numpy as np
import calendar

def main():
    happy = 0
    
    m1 = [4,6,9,11] #30日
    
    for i in np.arange(1,13):
    	if i == 2:
    		for j in np.arange(1,29):
    			count(i, j)
    	elif i in m1:
    		for j in np.arange(1,31):
    			count(i, j)
    	else:
    		for j in np.arange(1,32):
    			count(i, j)
    		
    print(happy)
    			
def count(i, j):
	global happy
	sum = j//10 + j%10 #10の位と1の位を足す
	if i == sum:
		happy += 1
		
if __name__ == "__main__":
    main()
# your code goes here