#include<bits/stdc++.h>
#define int unsigned long long
using namespace std;
inline char gc() {
    static char buf[1000010], *p1 = buf, *p2 = buf;
    return p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 1000010, stdin), p1 == p2) ? EOF : *p1++;
}
inline int read(){
    int res=0;
    char ch=gc();
    while(ch<'0'||ch>'9')
    	ch=gc();
    while(ch>='0'&&ch<='9'){
    	res=(res<<1)+(res<<3)+(ch^'0');
    	ch=gc();
    }
    return res;
}
static char buf[100];
int len = -1;
inline void flush() {
    fwrite(buf, 1, len + 1, stdout);
    len = -1;
}
inline void __PC(const char x) {
    if (len == 100)
        flush();
    buf[++len] = x;
}
inline void write(int x) {
    if (x > 9)
        write(x / 10);
    __PC(x % 10 ^ 48);
}
int n,a[50],ans;
void dfs(int now,int sum,int val){
	ans^=(sum*val);
	if(now>n)
		return;
#pragma unroll(20)
	for(int i=now;i<=n;++i)
		dfs(i+1,sum|(1<<i-1),val^a[i]);
}
signed main(){
	n=read();
	for(int i=1;i<=n;++i)
		a[i]=read();
	dfs(1,0,0);
	write(ans);
	flush();
    return 0;
}