mt19937_64 randdev(8901016);
inline int rand(int l, int h) { return uniform_int_distribution<int>(l, h)(randdev); }


int N,M,A[100010];
int ss[100010],x;
int ans[100010],best;

{
    rd(N,M,A(N));
    REP(i,M) x ^= A[i], ss[i] = i;
    
    REP(_,10){
        int j = rand(0,M-1);
        int k = rand(0,N-1);
        x ^= A[ss[j]];
        x ^= A[k];
        ss[j] = k;
        if (x > best){
            best = x;
            if (_ > N/10){
                copy(ss,ss+M,ans);
            }
        }
    }
    REP(i,M)
        wtSp(A[ss[i]]);
}