#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)
#define Inf 1000000001

mint dp[4005][4005];
mint sum[8005][4005];
int main(){
	
	
	dp[0][0] = 1;
	
	rep(i,4005){
		rep(j,4005){
			if(i!=4004)dp[i+1][j] += dp[i][j];
			if(j!=4004)dp[i][j+1] += dp[i][j];
			if(i!=4004&&j!=4004)dp[i+1][j+1] += dp[i][j]*2;
		}
	}
	
	int center = 4002;
	
	rep(i,4001){
		rep(j,4001){
			sum[i-j + center][i] += dp[i][j];
		}
	}
	
	rep(i,8005){
		rep(j,4004){
			sum[i][j+1] += sum[i][j];
		}
	}
	
	int q;
	cin>>q;
	
	rep(_,q){
		int x,y;
		scanf("%d %d",&x,&y);
		mint ans = 0;
		
		int t = x-y;
		
		int l = max(0,t);
		int r = min(x,t+y);
		t += center;
		//cout<<l<<','<<r<<endl;
		if(l<=r){
			ans += sum[t][r];
			if(l!=0)ans -= sum[t][l-1];
		}
		
		printf("%d\n",ans.val());
	}
			
	
	return 0;
}