n=int(input())
i=0

while i<n:
    j,k=0,0
    hh=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
    dd=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
    a,b=map(int,input().split())
    while j<a:
        c,d=map(int,input().split())
        for p in range(c,d+1):
            hh[p]=1
        j+=1
    while k<b:
        e,f=map(int,input().split())
        for q in range(e,f+1):
            dd[q]=1
        k+=1
    z=0
    cnt=0
    while z<24:
        if hh[z]==1 and dd[z] == 1:
            cnt=cnt+1
        z=z+1
    print(cnt)

    i+=1