#include<bits/stdc++.h>
using namespace std;
int main(){
    unsigned long long a,e[10000000],q=0,ee[10000000]={0},dd=0,d[1000000]={0};
    cin>>a;
    for(int i=1;i<=a;i++){
        cin>>e[i];
        if(d[e[i]]!=0&&d[e[i]]%2==1&&i%2==1||d[e[i]]!=0&&d[e[i]]%2==0&&i%2==0){
			q--;
			d[e[i]]=i;
		}
		else if(e[i]==e[i-1]&&i%2==0){
			q++;
		}
		else if(d[e[i]]!=0&&d[e[i]]%2==1&&i%2==0||d[e[i]]!=0&&d[e[i]]%2==0&&i%2==1){
			d[e[i]]=0;
			
		}
		
	}
    sort(e+1,e+1+a);
    for(int i=1;i<=a;i++){
        if(ee[e[i]]!=1){
        	if(e[i]==e[i+1]){
        		q++;
				ee[e[i]]=1;
			}
		}
    }
    cout<<q;
}