t = eval(input())
for _t in range(t):
        n, m = map(int, input().split())
        p = [0 for i in range(24)]
        q = [0 for i in range(24)]
        for i in range(n):
                x, y = map(int, input().split())
                for pos in range(x, y+1):
                        p[pos] = 1
        for i in range(m):
                x, y = map(int, input().split())
                for pos in range(x, y+1):
                        q[pos] = 1
        ans = 0
        for i in range(24):
                if p[i] == q[i] and p[i] == 1: ans += 1
        print(ans)