def rddata(arr,n):
	for j in range(n):
		s,e = map(int, raw_input().split())
		for k in range(s,e+1):
			arr[k] = 1

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