#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll mwf(ll n, ll m, ll a, ll b, ll c, ll d){
    a += c / m * b;
    c %= m;
    ll s = d / m * b;
    d %= m;
    ll y = (c * (n - 1) + d) / m, r = max(s, s + a * (n - 1) + b * y);
    return (y > 0) * a * b < 0 ? max(r, s + (a + b) * (a < 0) + mwf(y, c, b, a, m, m - d - 1)) : r;
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    ll t, n, m, a, b, c, d;
    cin >> t;
    while(t--){
        cin >> n >> m >> a >> b >> c >> d;
        cout << mwf(n, m, a, b, c, d) << "\n";
    }
    return 0;
}