t=int(input())
for i in range(0,t):
    cc=input().split()
    n=int(cc[0])
    m=int(cc[1])  

    hh=[0 for h in range(0,24)]
    dd=[0 for h in range(0,24)]

    s=0
    for nn in range(0,n):
        cc=input().split()
        a=int(cc[0])
        b=int(cc[1])
        while a<=b:
            hh[a]=1
            a+=1
    for mm in range(0,m):
        cc=input().split()
        c=int(cc[0])
        d=int(cc[1])
        while c<=d:
            dd[c]=1
            c+=1
    for j in range(0,24):
        if hh[j]==1 and dd[j]==1:
            s=s+1
    print(s)