#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <atcoder/modint>
#include <atcoder/math>
using namespace std;
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(int i=0; i<(int)(n); i++)
const i64 INF = 1001001001001001001;

using Modint = atcoder::static_modint<998244353>;

template<class modint>
modint TriangleSumTimesLinear(
    long long n,
    long long a,
    long long b,
    modint c,
    modint d,
    modint e
){
    if(n <= 0) return modint(0);
    if(a < b) return TriangleSumTimesLinear(n, b, a, d, c, e);

    long long maxi = (n - 1) / a + 1;
    modint offset = 0;
    offset += c * modint(maxi) * modint(maxi-1) * modint(maxi+1) / modint(6);
    offset += d * modint(maxi) * modint(maxi-1) * modint(maxi+1) / modint(6);
    offset += e * modint(maxi) * modint(maxi+1) / modint(2);
    return offset + TriangleSumTimesLinear(n-maxi*b, b, a-b, d, c-d, e+d*modint(maxi));
}

template<class modint>
modint AKindOfFloorSum(
    long long n,
    long long m,
    long long a,
    long long b
){
    long long q = b / m;
    modint tmp = modint(n) * modint(n-1) / 2 * q;
    b -= q * m;
    long long newn = a * (n-1) + b - (m-1);
    if(newn <= 0) return 0;
    return tmp + TriangleSumTimesLinear<modint>(newn, a, m, -1, 0, n-1);
}

template<class modint>
modint BKindOfFloorSum(
    long long n,
    long long m,
    long long a,
    long long b
){
    long long q = b / m;
    modint tmp = modint(n) * modint(n-1) / 2 * q;
    b -= q * m;
    long long newn = a * (n-1) + b - (m-1);
    if(newn <= 0) return 0;
    return tmp + TriangleSumTimesLinear<modint>(newn, a, m, 0, 0, 1);
}


using Modint1 = atcoder::static_modint<1000000007>;
using Modint2 = atcoder::static_modint<1000000009>;

template<class modint>
modint find_mod(
    long long N,
    long long M,
    long long X,
    long long Y
){
    modint x1 = AKindOfFloorSum<modint>(N, M, X, Y) * 2;
    modint x2 = BKindOfFloorSum<modint>(N, M, X, Y) * (1-N);
    modint x3 = AKindOfFloorSum<modint>(N, M, X, 0);
    modint x4 = BKindOfFloorSum<modint>(N, M, X, 0) * (-N);
    return x1 + x2 + x3 + x4;
}

int main(){
    int T; cin >> T;
    rep(t,T){
        long long N,M,X,Y; cin >> N >> M >> X >> Y;
        auto x1 = find_mod<Modint1>(N, M, X, Y);
        auto x2 = find_mod<Modint2>(N, M, X, Y);
        long long ans = atcoder::crt({ x1.val(), x2.val() }, { x1.mod(), x2.mod() }).first;
        cout << ans << '\n';
    }
    return 0;
}



struct ios_do_not_sync{
    ios_do_not_sync(){
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
    }
} ios_do_not_sync_instance;