#include <stdio.h>
#include <memory.h>

int max, Acount, Bcount, a[200][3], b[200][3], rec[40010][4];
int t, xtotal, ytotal, cur, flag[40010], ptr;

int CanCut(int xl, int yl, int xh, int yh)
{
	int i;
	for(i=0; i<Acount; i++)
	{
		if( (xl >= a[i][0]) && (xh <= a[i][1]) && (a[i][2] <yh ) && (a[i][2] > yl) )
		{
			rec[cur][0] = xl; rec[cur][1] = yl; rec[cur][2] = xh; rec[cur][3] = a[i][2]; flag[cur] = 1;
			cur++;
			rec[cur][0] = xl; rec[cur][1] = a[i][2]; rec[cur][2] = xh; rec[cur][3] = yh; flag[cur] = 1;
			cur++;
			return 1;
		}
	}
	for(i=0; i<Bcount; i++)
	{
		if( (yl >= b[i][0]) && (yh <= b[i][1]) && (b[i][2] < xh) && (b[i][2] > xl) )
		{
			rec[cur][0] = xl; rec[cur][1] = yl; rec[cur][2] = b[i][2]; rec[cur][3] = yh; flag[cur] = 1;
			cur++;
			rec[cur][0] = b[i][2]; rec[cur][1] = yl; rec[cur][2] = xh; rec[cur][3] = yh; flag[cur] = 1;
			cur++;
			return 1;
		}
	}
	return 0;
}

int works()
{
	int tmp, i;
	memset(rec, 0, sizeof(rec));
	memset(flag, 0, sizeof(flag));
	ptr=0,cur=1;
	flag[ptr]=1;
	rec[ptr][0]=rec[ptr][1]=0;
	rec[ptr][2]=xtotal; 
	rec[ptr][3]=ytotal;
	while(ptr<cur)
	{
		if(flag[ptr] && CanCut(rec[ptr][0], rec[ptr][1], rec[ptr][2], rec[ptr][3]) )
			flag[ptr]=0;   
		ptr++;
	}
	max = 0;
	for(i=0; i<cur; i++)
	{
		if(flag[i])
		{
			tmp=(rec[i][2]-rec[i][0])*(rec[i][3]-rec[i][1]);
			if(max<tmp)
				max=tmp;
		}
	}
	return max;
}

int Add(int res[][3], int len, int x, int y, int z)
{
	int i;
	int flag = 0;
	for(i=0; i<len; i++)
	{
		if(res[i][2] == z && res[i][1] < y && res[i][0] < x && x<=res[i][1])
		{
			res[i][1] = y;
			flag = 1;
		}
		if(res[i][2] == z && res[i][0] <= y && res[i][0] > x && y < res[i][1])
		{
			res[i][0] = x;
			flag = 1;
		}
		if(res[i][2] == z && res[i][0] <= x && res[i][1] >= y)
		{
			flag = 1;
			break;
		}
		if(res[i][2] == z && res[i][0] >= x && res[i][1] <= y)
		{
			res[i][0] = x;
			res[i][1] = y;
			flag = 1;
		}
	}
	if(!flag)
	{
		res[len][0] = x;
		res[len][1] = y;
		res[len][2] = z;
		len++;
	}
	return len;
}

int main()
{
	//freopen("D:\\in.txt", "r", stdin);
	//freopen("D:\\out.txt", "w", stdout);
	int i;
	int cases;
	int xl, yl, xh, yh;
	scanf("%d", &cases);
	while(cases--)
	{
		Acount = 0;
		Bcount = 0;
		memset(a, 0, sizeof(a));
		memset(b, 0, sizeof(b));
		scanf("%d%d", &xtotal, &ytotal);
		scanf("%d",&t);
		for(i=0; i<t; i++)
		{
			scanf("%d%d%d%d", &xl, &yl, &xh, &yh);
			Acount = Add(a, Acount, xl, xh, yl); //xl, xh是切割线的两端，yl表示是一个矩形的下面一段的切割线。
			Bcount = Add(b, Bcount, yl, yh, xh); //同理这个表示矩形右边的切割线。
		}
		printf("%d\n", works());
	}
	return 0;
}