#include<iostream>

#include<cstdio>

#include<cstdlib>

#include<cstring>

#include<cmath>

#include<map>

#include<set>

#include<vector>

#include<algorithm>

#include<stack>

#include<queue>

using namespace std;

#define INF 1000000000

#define eps 1e-8

#define pii pair<int,int>

#define LL long long int

int n,p;

int ans=;

int x[];

int main()

{

    //freopen("in7.txt","r",stdin);

    //freopen("out.txt","w",stdout);

    scanf("%d",&n);

    x[]=;

    for(int i=; i<=n; i++)

    {

        x[i]=x[i-]^(i-);

        int t=n/i;

        if(t%==)      ans^=x[i];

        ans^=x[n%i+];

    }

    for(int i=; i<n; i++)

    {

        scanf("%d",&p);

        ans^=p;

    }

    printf("%d\n",ans);

    //fclose(stdin);

    //fclose(stdout);

    return ;

}