// you can also use imports, for example:
// import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(int[] A) {
        // write your code in Java SE 8
    }
}

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    pass

def solution(A):
    check = {}
    for i in range(len(A)):
        check[A[i]] = check.get(A[i], 0) + 1
    return len(check.keys())

def solution(A):
    check = {}
    for i in range(len(A)):
        check[A[i]] = check.get(A[i], 0) + 1
    return len(check.keys())

def solution(A):
    check = {}
    for i in range(len(A)):
        check[A[i]] = check.get(A[i], 0) + 1
    return len(check.keys())

def solution(A):
    check = {}
    for i in range(len(A)):
        check[A[i]] = check.get(A[i], 0) + 1
    return len(check.keys())