How Many Distinct Categories?

Riverbend Supply's returns desk stamps every returned item with a reason code. The monthly summary opens with a single figure: how many different reasons came up at all this month. How often each one was used does not matter to that line — a reason given ninety times and a reason given once each count for one. The codes arrive in the order the returns were processed, with repeats scattered through the file.

Task: Print how many different reason codes appear.

Input

The first line holds a single integer n, the number of returns. Each of the next n lines holds one reason code: a whole number. Codes may repeat, and repeats are not necessarily next to each other.

Output

One line holding the number of different codes, as a whole number.

Example:

Input:
5
1
2
1
3
2

Output:
3