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