#include <bits/stdc++.h> 
using namespace std;
using ll =long long;
#define all(v) v.begin(),v.end()
 #define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)

ll INF=2e18;

const int mod = 998244353;

class mint {
    long long x;
public:
    mint(long long x=0) : x((x%mod+mod)%mod) {}
    mint operator-() const { 
      return mint(-x);
    }
    mint& operator+=(const mint& a) {
        if ((x += a.x) >= mod) x -= mod;
        return *this;
    }
    mint& operator-=(const mint& a) {
        if ((x += mod-a.x) >= mod) x -= mod;
        return *this;
    }
    mint& operator*=(const  mint& a) {
        (x *= a.x) %= mod;
        return *this;
    }
    mint operator+(const mint& a) const {
        mint res(*this);
        return res+=a;
    }
    mint operator-(const mint& a) const {
        mint res(*this);
        return res-=a;
    }
    mint operator*(const mint& a) const {
        mint res(*this);
        return res*=a;
    }
    mint pow(ll t) const {
        if (!t) return 1;
        mint a = pow(t>>1);
        a *= a;
        if (t&1) a *= *this;
        return a;
    }
    // for prime mod
    mint inv() const {
        return pow(mod-2);
    }
    mint& operator/=(const mint& a) {
        return (*this) *= a.inv();
    }
    mint operator/(const mint& a) const {
        mint res(*this);
        return res/=a;
    }

    friend ostream& operator<<(ostream& os, const mint& m){
        os << m.x;
        return os;
    }
};

ll mod_pow(ll x,ll n,ll mod) {
ll res=1;
  while(n>0) {
if(n&1) {
res=res*x%mod;
}
   x=x*x%mod;
    n>>=1;
  }
return res;
}
 

 mint floor_sum(long long n, long long m, long long a, long long b) {
    mint ans = 0;
 
 ll t=mod_pow(2,mod-2,mod);

    if (a >= m) {
        ans += (n - 1)%mod *( n%mod)%mod * ((a / m)%mod)%mod *t%mod;
        a %= m;
    }
    if (b >= m) {
        ans += n %mod* ((b / m)%mod)%mod;
        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) %mod*( y_max%mod);
    ans += floor_sum(y_max, a, m, (a - x_max % a) % a);
    return ans;
}



void solve() {
ll N,M,L,R;cin>>N>>M>>L>>R;
mint ans=floor_sum(R+1,N-1,1,0)-floor_sum(L,N-1,1,0); 

ans+=floor_sum(M-L+1,N-1,1,0)-floor_sum(M-R,N-1,1,0);

ans+=(R-L+1);

cout<<ans<<endl;




}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  ll t;cin>>t;
  for(ll i=0;i<t;i++) {
    solve();
  }

}