T = int(input())

while T>0:
    n,m=list(map(int,input().split()))
    ln,lm = [0]*24,[0]*24
    for i in range(n):
        s,e = list(map(int,input().split()))
        for j in range(s,e+1):
            ln[j] = 1
    for i in range(m):
        s,e = list(map(int,input().split()))
        for j in range(s,e+1):
            lm[j] = 1
    sum = 0
    for i in range(24):
        if ln[i] == 1 and lm[i] == 1:
            sum +=1
    print(sum)
    T-=1