day = [31,28,31,30,31,30,31,31,30,31,30,31]

ans=0
for i in range(1,13):
    for j in range(1,day[i-1]+1):
        temp = str(j).zfill(2)
        if i == int(temp[0])+int(temp[1]):
            ans+=1

print(ans)