[HackerRank] 03. Sock Merchant

def sockMerchant(n, arr):
    unique_sock = set(arr)
    result = 0 
    
    for i in unique_sock:
        count = arr.count(i)
        result += count // 2
    return result

def main():
    n = int(input())
    arr = list(map(int, input().strip().split()))
    result = sockMerchant(n, arr)
    print(result)
    
if __name__ == '__main__':
    main()