#include<iostream>
using namespace std;
const int N=1e6+10;
int t,n,m,c,a[N];
int px(int r){
	return r/m;
}
int py(int r){
	return r%m;
}
int pz(int x,int y){
	return x*m+y;
}
bool check(int r){
	int rx=px(r);
	int ry=py(r);
	int nx=px(r+1);
	int ny=py(r+1);
	if(rx<=nx&&ry<=ny)return true;
	if(rx>=nx&&ry>=ny)return true;
	return false;
}
int main(){
	cin>>t;
	while(t--){
		cin>>n>>m;
		for(int i=0;i<=n*m-1;i++)
			cin>>c,a[c]=i;
		int ans=0;
		while(check(ans))ans++;
		cout<<ans+1<<endl;
	}
	return 0;
}