public static int sockMerchant(int n, List<Integer> ar) {
        int pairs = 0;
        int size = ar.size();
        while(size-- > 0){
            int sock = ar.get(0);
            ar.remove(0);
	        if (ar.contains(sock)){
	            pairs++;
	            ar.remove(ar.indexOf(sock));
	            size--;
	            }
	        }
        return pairs;
}