#include<bits/stdc++.h>
using namespace std;
long long nyh[1510101],cj[1510101],ans[1010111],tans=0,tn=0,m1;
long long mod=998244353;
long long poww(long long z,long long cs) {
	long long tans=1,d=z;
	while(cs) {
		if(cs%2)
			tans*=d;
		tans=tans%mod;
		cs/=2;
		d=d*d;
		d=d%mod;
	}
	return tans;
}
long long c(long long n,long long m) {
	return cj[n]*nyh[m]%mod*nyh[n-m]%mod;
}
long long s,s1,t;
struct xing {
	long long n,m,w;
};
bool  operator < (xing a,xing b) {
	if(a.n/1000!=b.n/1000) {
		return a.n/1000>b.n/1000;
	} else {
		return a.m>b.m;
	}
}
priority_queue<xing> qe;
void lr() {
	tans=tans*2-c(tn-1,m1-1);
	tans=(tans+mod)%mod;
	tn++;
}
void ll() {
	tn--;
	tans=(tans+c(tn-1,m1-1))*nyh[2];
	tans=(tans+mod)%mod;
}
void rr() {
	m1++;
	tans=tans+c(tn-1,m1-1);
	tans=(tans+mod)%mod;
}
void rl() {
	tans=tans-c(tn-1,m1-1);
	tans=(tans+mod)%mod;
	m1--;
}
int main() {
	cin>>t;
	cj[0]=1;
	nyh[0]=1;
	for(int i=1; i<=360000; i++) {
		cj[i]=(cj[i-1]*i)%mod;
		nyh[i]=(nyh[i-1]*poww(i,mod-2))%mod;
	}
	for(int i=1; i<=t; i++) {
		cin>>s>>s1;
		qe.push({s,s1,i});
	}
	tn=1;
	m1=1;
	tans=1;
	while(!qe.empty()) {
		while(tn<qe.top().n)
			lr();
		while(tn>qe.top().n)
			ll();
		while(m1<qe.top().m)
			rr();
		while(m1>qe.top().m)
			rl();
		tans=(tans+mod)%mod;
		ans[qe.top().w]=tans%mod*(poww(2,tn)-1)%mod;
		qe.pop();
	}
	for(int i=1; i<=t; i++) {
		cout<<ans[i]%mod<<endl;
	}
}