N=int(input())
A=[int(i) for i in input (). split ()]
i=0
while i<len(A):
    j=i+1
    e=1
    while j<len(A) and e==1:
        if A[i]==A[j]:
            A.pop(i)
            A.pop(j-1)
            e=0
            i-=1
            j-=1
        j+=1
    i+=1
print (len(A))