days=[day for day in range(1,32)]
mths = [0,31,28,31,30,31,30,31,31,30,31,30,31]
count=0
count_list=[]
for day in days:
    if day<=12:
        count+=1
        count_list.append(day)
    else:
        sumday=day//10+day%10
        if (sumday<=12) & (day<=mths[sumday]):
            count+=1
            count_list.append(day)
print(count)