#include<bits/stdc++.h>
#define MAX 2005
#define ll long long
using namespace std;
const ll mod=998244353;
ll qm(ll x){
    if(x>=mod) x-=mod;
    return x;
}
ll fpow(ll a,ll b){
	ll r=1;
	while(b){
		if(b&1) r=r*a%mod;
		a=a*a%mod; b>>=1;
	} return r;
}
ll inv(ll x){ return fpow(x,mod-2); }
ll x[MAX],y[MAX],len;
ll lglr(ll k){
    ll r=0;
    for(int i=1;i<=len;i++){
		ll top=1,bot=1;
		for(int j=1;j<=len;j++){
			if(j==i) continue;
			top=top*qm(k-x[j]+mod)%mod;
		}
		for(int j=1;j<=len;j++){
			if(j==i) continue;
			bot=bot*qm(x[i]-x[j]+mod)%mod;
		}
		top=top*inv(bot)%mod;
		r=qm(r+top*y[i]%mod);
	}return r;
}
ll n,k;
struct node{
    int l,r;
}p[MAX];
ll c[MAX],cc;
ll get(ll mid){
    ll r=0;
    ll f0=1,f1=0;
    for(int i=1;i<=n;i++){
        ll t1=max(p[i].r-mid+1,0ll),t0=max(mid-p[i].l,0ll);
        if(mid<p[i].l) t1=p[i].r-p[i].l+1;
        if(mid>p[i].r) t0=p[i].r-p[i].l+1;
        t0%=mod;t1%=mod;
        r=qm(r*qm(t0+t1)%mod+f1*t1%mod);
        ll g0=qm(f0+f1)*t0%mod;
        ll g1=f0*t1%mod;
        f0=g0,f1=g1;
    }return r;
}
ll sol(int L,int R){
    ll r=0;
    if(R-L+1<=n+1){
        for(int i=L;i<=R;i++)
            r=qm(r+get(i));
    }else{
        ll sm=0;len=n+1;
        for(int i=L;i<=L+n+1;i++){
            sm=qm(sm+get(i));
            x[i-L+1]=i;y[i-L+1]=sm;
        }return lglr(R);
    }
    return r;
}
void calc(){
    cin>>n;cc=0;
    for(int i=1;i<=n;i++){
        cin>>p[i].l;c[++cc]=p[i].l;
    }c[++cc]=1;
    for(int i=1;i<=n;i++){
        cin>>p[i].r;
        c[++cc]=p[i].r+1;
    }
    sort(c+1,c+1+cc);
    cc=unique(c+1,c+1+cc)-c-1;
    ll ans=0;
    for(int i=1;i<cc;i++)
        ans=qm(sol(c[i],c[i+1]-1)+ans);
    cout<<ans<<"\n";
}
int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    int t;cin>>t;
    while(t--) calc();
}