B=[1,3,5,7,8,10,12]
S=[4,6,9,11]
C=0
for i in range(10):
    if 2==i:
        C+=1
for i in range(10,29):
    if i==int(str(i)[0])+int(str(i)[1]):
        C+=1
for i in range(len(B)):
    for j in range(10):
        if B[i]==j:
            C+=1
    for j in range(10,32):
        if B[i]==int(str(j)[0])+int(str(j)[1]):
            C+=1
for i in range(len(S)):
    for j in range(10):
        if S[i]==j:
            C+=1
    for j in range(10,31):
        if S[i]==int(str(j)[0])+int(str(j)[1]):
            C+=1
print(C)