import copy
import heapq
import itertools
import math
import operator
import sys
from bisect import bisect, bisect_left, bisect_right, insort
from collections import Counter, deque
from fractions import Fraction
from functools import cmp_to_key, lru_cache, partial
from inspect import currentframe
from math import ceil, gcd, log10, pi, sqrt

# import pypyjit
# pypyjit.set_param('max_unroll_recursion=-1')
input = sys.stdin.readline
sys.setrecursionlimit(10000000)
# mod = 10 ** 9 + 7
mod = 998244353
# mod = 1 << 128
# mod = 10 ** 30 + 1
INF = 1 << 61
DIFF = 10 ** -9
DX = [1, 0, -1, 0, 1, 1, -1, -1]
DY = [0, 1, 0, -1, 1, -1, 1, -1]

def read_values(): return tuple(map(int, input().split()))
def read_index(): return tuple(map(lambda x: int(x) - 1, input().split()))
def read_list(): return list(read_values())
def read_lists(N): return [read_list() for _ in range(N)]
def dprint(*values): print(*values, file=sys.stderr)
def dprint2(*values):
    names = {id(v): k for k, v in currentframe().f_back.f_locals.items()}
    dprint(", ".join(f"{names.get(id(value), '???')}={repr(value)}" for value in values))


def solve():
    N, M, A, B, C, D = read_values()

    def f(N, M, A, B, C, D, K):
        assert(0 <= C < M)
        assert(0 <= D < M)
        if N == 0:
            return 0

        def v(x):
            return A * x + B * ((C * x + D) // M) + K
        
        # res = max(v(i) for i in range(N))
        # print(f"{N=}, {M=}, {A=}, {B=}, {C=}, {D=}, {K=}: {res=}")

        if C == 0 or A * B >= 0:
            return max(v(0), v(N - 1))

        m, r1 = M // C, M % C
        d, r2 = D // C, D % C
        if A > 0:
            while r1 - r2 - 1 < 0:
                r2 -= C
                d += 1
            # print("--A--")
            return max(f(
                min(N, (C * N + D + M - 1) // M - 1),
                C,
                m * A + B,
                A,
                r1,
                r1 - r2 - 1,
                A * (m - d) + K,
            ), v(N - 1))
        else:
            while r1 - r2 - 1 < 0:
                r2 -= C
                d += 1

            # print("--B--")
            return max(v(0), f(
                min(N, (C * N + D + M - 1) // M - 1), 
                C,
                m * A + B,
                A,
                r1,
                r1 - r2 - 1,
                A * (m + 1 - d) + B + K,
            ))
    
    return f(N, M, A, B, C, D, 0)


def main():
    T = int(input())
    res = []
    for _ in range(T):
        res.append(solve())
    print(*res, sep="\n")


if __name__ == "__main__":
    main()