t=int(input())
for i in range(t):
	n,m=map(int,raw_input().strip().split())
	lh=[0 for i in range(24)]
	ld=[0 for i in range(24)]
	for j in range(n):
		a,b=map(int,raw_input().strip().split())
		for k in range(a,b+1):
			lh[k]=1
	for j in range(m):
		a,b=map(int,raw_input().strip().split())
		for k in range(a,b+1):
			ld[k]=1
	x=0
	for j in range(24):
		if ld[j]==lh[j] and ld[j]==1:
			x+=1
	print x