import sys
from typing import List

def main(_: int, m: int, l: List[int], r: List[int]):
    if not (sum(l) <= m <= sum(r)):
        return -1
    
    if m == sum(l):
        return (m * m - sum(e * e for e in l)) // 2
    
    tl, tr = 0, 10 ** 9 + 10
    while abs(tr - tl) > 1:
        t = (tl + tr) // 2
        sum_t = 0
        for i in range(n):
            sum_t += max(l[i], min(t, r[i]))
        if sum_t < m:
            tl = t
        else:
            tr = t

    t0 = tl

    sum_t0 = 0
    for i in range(n):
        sum_t0 += max(l[i], min(t0, r[i]))

    d = m - sum_t0

    x = 0
    for i in range(n):
        a, b = l[i], r[i]
        c = max(a, min(t0, b))
        if d > 0 and a <= t0 < b:
            c += 1
            d -= 1
        x += c * c
    
    return (m * m - x) // 2

if __name__ == '__main__':
    t = int(sys.stdin.readline().rstrip())
    answers = []
    for _ in range(t):
        n, m = map(int, sys.stdin.readline().rstrip().split())
        l = list(map(int, sys.stdin.readline().rstrip().split()))
        r = list(map(int, sys.stdin.readline().rstrip().split()))
        answers.append(main(n, m, l, r))
    print('\n'.join(map(str, answers)))