Sock Merchant

import math

def sockMerchant(n, ar):
    Socks = ar.split(" ")
    Checked_Socks = []
    Counter = 0
    for Sock in Socks:
        if Sock not in Checked_Socks:
            N = Socks.count(Sock)
            if N > 1:
                Counter += int(math.trunc(N/2))
            Checked_Socks.append(Sock)
    return Counter