#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using ll = long long;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int T;
    cin >> T;
    while(T--){
        ll N, M, A, B, C, D;
        cin >> N >> M >> A >> B >> C >> D;
        auto rec = [&](auto rec, ll n, ll m, ll a, ll b, ll c, ll d) -> ll {
            assert(c >= 0 && d >= 0);
            ll dc = c / m, dd = d / m, ofs = 0;
            // Ax + B[(Cx + D) / M] -> (A + [BC / M]) x + [BD / M]
            a += b * dc;
            c -= dc * m;
            ofs += b * dd;
            d -= dd * m;
			
			// floor((C(N-1) + D) / M) の最大値
            ll num = (c * (n - 1) + d) / m;
            ll res = ofs + max(0ll, a * (n - 1) + b * num);
            if((!(a >= 0) ^ (b >= 0)) || num == 0) return res;

            if(a < 0){
                res = max(res, ofs + b + rec(rec, num, c, b, a, m, m + c - 1 - d));
            }else{
                res = max(res, ofs + rec(rec, num, c, b, a, m, m - d - 1));
            }
            return res;
        };

        cout << rec(rec, N, M, A, B, C, D) << '\n';
    }
}