Birthdays

If somebody in Summer Computer School (SCS) has a birthday, the celebration is arranged. Help organizers to find out how many times they must arrange the birthday parties during SCS.August.

Input

First number contains the amount of SCS - children, who celebrates their birthdays in August, then in the same line given the dates of their birthdays. The number of birthdays in SCS.August is no more than 300.

Output

Print the number of days with birthdays celebration.

Examples