D = [0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
ans = 0
for i in range(1, 13):
    for d in range(1, D[i] + 1):
        if i == d // 10 + d % 10:
            ans += 1
print(ans)