#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
#define rep(i, n) for(int i=0;i<(n);++i)
#define rep1(i, n) for(int i=1;i<=(n);i++)
#define ll long long
using mint = modint998244353;
using P = pair<ll,ll>;
using lb = long double;
using T = tuple<ll, ll, ll>;
#ifdef LOCAL
#  include <debug_print.hpp>
#  define dbg(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define dbg(...) (static_cast<void>(0))
#endif

mint floor_s(long long n, long long m, long long a, long long b) {
    mint ans = 0;
    if (a >= m) {
        ans += mint(n - 1) * mint(n) * mint(a / m) / 2;
        a %= m;
    }
    if (b >= m) {
        ans += mint(n) * mint(b / m);
        b %= m;
    }

    long long y_max = (a * n + b) / m, x_max = (y_max * m - b);
    if (y_max == 0) return ans;
    ans += (n - (x_max + a - 1) / a) * y_max;
    ans += floor_s(y_max, a, m, (a - x_max % a) % a);
    return ans;
}

int main()
{
	int t;
	cin >> t;
	while(t--){
		ll n, m, l, r;
		cin >> n >> m >> l >> r;
		mint ans = 0;
		ans = floor_s(r+1, n-1, 1,0) - floor_s(l, n-1, 1, 0) + floor_s(m-l+1, n-1, 1, 0) - floor_s(m-r, n-1, 1, 0);
		ans += r- l + 1;
		cout << ans.val() << endl;
	}
	return 0;
}