#include <bits/stdc++.h>
static char buf[1000000],*paa=buf,*pd=buf;
static char buf2[1000000],*pp=buf2;
#define getchar() paa==pd&&(pd=(paa=buf)+fread(buf,1,1000000,stdin),paa==pd)?EOF:*paa++
inline void pc(char ch){
	if(pp-buf2==1000000) fwrite(buf2,1,1000000,stdout),pp=buf2;
	*pp++=ch;
}
inline void pcc(){
	fwrite(buf2,1,pp-buf2,stdout);
	pp=buf2;
}
inline int read(void){
	int w=1;
	register int x(0);register char c(getchar());
	while(c<'0'||c>'9'){if(c=='-') w=-1;c=getchar();}
	while(c>='0'&&c<='9')x=(x<<1)+(x<<3)+(c^48),c=getchar();
	return w*x;
}
void write(int x){
	static int sta[20];
	int top=0;
	do{
		sta[top++]=x%10,x/=10;
	}while(x);
	while(top) pc(sta[--top]+48);
}
void we(int x){
	write(x);
	pc('\n');
}
int C,T,N,M,a[1000009];
signed main(void) {
	C=read();T=read();
	while(T--) {
		N=read();M=read();
		int ss=0;
		for(int i=1;i<=N;i++) {
			a[i]=read();
			ss^=a[i];
		}
		long long aq=0;
		for(int i=30;i>=0;i--) {
			bool ff=0;
			ss=0;
			for(int j=1;j<=N;j++) {
				if((a[j]>>i)&1) ff^=1;
				ss^=a[j];
			}
			if(ff) {
				int ans=(1<<31)-1;
				for(int j=1;j<=N;j++) {
					if((a[j]>>i)%2==0) {
						int x=(a[j]&((1<<i)-1));
						ans=std::min(ans,(1<<i)-x);
					}
				}
				for(int j=1;j<=N;j++) {
					if((a[j]>>i)%2==0) {
						int x=(a[j]&((1<<i)-1));
						if(ans==(1<<i)-x) {
							a[j]+=(1<<i)-x;
							aq+=(1<<i)-x;
							break;
						}
					}
				}
			}
		}	
		printf("%lld\n0\n",aq);	
	}
}