#include <bits/stdc++.h>
using namespace std;
const int N = 400 + 10;
int v[N];
int aans,n,m,T;
int val[N];
int a[N][N];
int read(){
	char ch; int sum = 0,flag = 1;
	ch = getchar();
	while(ch < '0' || ch > '9'){if(ch == '-') flag = -flag; ch = getchar();}
	while(ch >= '0' && ch <= '9'){sum = sum * 10 + ch - '0'; ch = getchar();}
	return sum * flag;
}
int ans[1024 * 1024 * 2 + 1];
void Work1(){
	memset(v,0,sizeof(v));
	for(int i = 1; i <= n; i++){
		int sum = 0;
		for(int j = 1; j <= m; j++){
			sum = sum * 2 + a[i][j];
		}
		v[i] = sum;
	}
	memset(ans,0x3f,sizeof(ans));
	ans[0] = 0;
	for(int i = 0; i <= (1 << m) - 1; i++){
		for(int j = 1; j <= n; j++){
			ans[i | v[j]] = min(ans[i | v[j]],ans[i] + 1);
		}
	}
	printf("%d\n",ans[(1 << m) - 1]);
	return ;
}
void dfs(int id,int tar,int cos){
	if(id == n + 1){
		if(tar == m){
			aans = min(aans,cos);
		}
	    return ;
	}
	int res = 0;
	for(int i = 1; i <= m; i++) {
		if(!val[i] && a[id][i]) res++;
		val[i] += a[id][i];
	}
	dfs(id + 1,tar + res,cos + 1);
	for(int i = 1; i <= m; i++) val[i] -= a[id][i];
	dfs(id + 1,tar,cos);
}
void Work2(){
	aans = m + 1;
	dfs(1,0,0);
	printf("%d\n",aans);
	return ;
}

int main(){
	T = read();
	while(T--){
		n = read(); m = read();
		memset(a,0,sizeof(a));
		for(int i = 1; i <= n; i++){
			for(int j = 1; j <= m; j++){
				a[i][j] = read();
			}
		}
		if(m <= 20){
			Work1();
		}
		else if(n <= 20){
			Work2(); 
		}
	}
	return 0;
}