#include<bits/stdc++.h>
#define int long long
#define PII pair<int,int>
#define fir first
#define sec second
using namespace std;
const int B=450,mod=998244353;
int q;
int f[500005],inv[500005],F[500005];
int ans[500005];
struct node{
	int x,y,id;
} a[200005];
bool cmp(node x,node y){
	if(x.x/B!=y.x/B) return x.x/B<y.x/B;
	return x.y<y.y;
}
int calc(int a,int b){
	if(b==0) return 1;
	int t=calc(a,b/2);
	if(b%2==0)
		return t*t%mod;
	return t*t%mod*a%mod;
}
int C(int a,int b){
	return f[a]*inv[a-b]%mod*inv[b]%mod;
}
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	f[0]=1;
	F[0]=inv[0]=1;
	for(int i=1;i<=500000;i++){
		f[i]=f[i-1]*i%mod;
		inv[i]=calc(f[i],mod-2);
		F[i]=F[i-1]*2%mod;
	}
	cin>>q;
	for(int i=1;i<=q;i++){
		cin>>a[i].x>>a[i].y;
		a[i].y--,a[i].x--;
		a[i].id=i;
	}
	sort(a+1,a+1+q,cmp);
	int l=1,r=1,s=1;
	for(int i=1;i<=q;i++){
		while(l<a[i].x){
			l++;
			s=(s*2+1-C(l-1,r)+mod)%mod;
		}
		while(r<a[i].y){
			r++;
			(s+=C(l,r))%=mod;
		}
		while(a[i].y<r){
			s=(s+mod-C(l,r))%mod;
			r--;
		}
		while(a[i].x<l){
			s=(s-1+C(l-1,r)+mod)%mod*calc(2,mod-2)%mod;
			l--;
		}
		ans[a[i].id]=(F[a[i].x+1]+mod-1)*(s+1)%mod;
	}	
	for(int i=1;i<=q;i++){
		cout<<ans[i]<<'\n';
	}
	return 0;
}