t=int(raw_input())
for t in range(t):
	n,m=map(int,raw_input().strip().split())
	a=[0 for i in range(24)] 
	for i in range(n):
		x,y=map(int,raw_input().strip().split())
		for j in range(x,y+1):
			a[j]=1

	b=[0 for i in range(24)] 
	for i in range(m):
		x,y=map(int,raw_input().strip().split())
		for j in range(x,y+1):
			b[j]=1
	
	sum=0
	for i in range(24):
		if a[i]==1 and b[i]==1:
			sum=sum+1
		
	print sum