Problem:
Score : 200 points

Problem Statement

An X-layered kagami mochi (X ≥ 1) is a pile of X round mochi (rice cake) stacked vertically where each mochi (except the bottom one) has a smaller diameter than that of the mochi directly below it. For example, if you stack three mochi with diameters of 10, 8 and 6 centimeters from bottom to top in this order, you have a 3-layered kagami mochi; if you put just one mochi, you have a 1-layered kagami mochi.

Lunlun the dachshund has N round mochi, and the diameter of the i-th mochi is d_i centimeters. When we make a kagami mochi using some or all of them, at most how many layers can our kagami mochi have?

Constraints

1 ≤ N ≤ 100

1 ≤ d_i ≤ 100

All input values are integers.

Input

Input is given from Standard Input in the following format:

N
d_1
:
d_N

Output

Print the maximum number of layers in a kagami mochi that can be made.

Sample Input 1

4
10
8
8
6

Sample Output 1

3

If we stack the mochi with diameters of 10, 8 and 6 centimeters from bottom to top in this order, we have a 3-layered kagami mochi, which is the maximum number of layers.

Sample Input 2

3
15
15
15

Sample Output 2

1

When all the mochi have the same diameter, we can only have a 1-layered kagami mochi.

Sample Input 3

7
50
30
50
100
50
80
30

Sample Output 3

4

Solution in Go (1.6) (judge verdict: Accepted)

// Package main provides
//
// File:  b.go
// Author: ymiyamoto
//
// Created on Thu Jan  3 12:23:33 2019
//
package main

import (
	"fmt"
	"sort"
)

func main() {
	var N int
	fmt.Scan(&N)
	ds := make([]int, N)

	for i := range ds {
		fmt.Scan(&ds[i])
	}

	sort.Ints(ds)

	ans := 0
	current := 0
	for i := range ds {
		if current < ds[i] {
			current = ds[i]
			ans++
		}
	}
	fmt.Println(ans)
}