Without using xor operator

# a.sort()
    # for i in range(0,len(a)-1,2):
    #     if (a[i] == a[i+1]):
    #         continue
    #     else:
    #         return a[i]
            
    # return a[len(a)-1]
		
		#Using XOR operator
		
    result=0
    for i in a:
        result^=i
    return result