#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;

const int maxn = 10010;

int T, n, m, x, cnt, ans, tot;
int a[maxn];

int f_;
char ch_;
template <class T>
	inline T read(T &x_){
		x_ = 0, f_ = 1, ch_ = getchar();
		while (!isdigit(ch_)) {if (ch_ == '-') f_ = -1; ch_ = getchar();}
		while (isdigit(ch_)){x_ = (x_ << 3) + (x_ << 1) + ch_ - 48; ch_ = getchar();}
		return x_ *= f_;
	}

int main(){
	freopen ("happygameT1.in", "r", stdin);
	freopen ("happygameT1.out", "w", stdout);
	read(T);
	for (; T; --T){
		read(n);
		read(m);
		cnt = 0; tot = 0; ans = 0;
		for (register int i = 1;i <= n; ++i)	
			for (register int j = 1;j <= m; ++j){
				read(x);
				a[++cnt] = x;
			}
		sort (a + 1, a + cnt + 1);
		for (register int i = cnt;i >= 1; --i){
			ans += a[i];
			tot++;
			if (tot == n) break;
		}
		printf ("%d\n", ans);
	}
	return 0;
}