#include <iostream>

using namespace std;
typedef long long ll;
int dp[4010][4010][2][2] = {},mod = 998244353;
int sum[4010][4010] = {};
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int i,j,k,l;
    dp[0][0][0][1] = dp[0][0][1][1] = 1;
    for(i=0;i<=4000;i++){
        for(j=0;j<=4000;j++){
            (dp[i + 1][j][0][0] += (dp[i][j][0][0] + dp[i][j][0][1])%mod) %= mod;
            (dp[i][j + 1][1][0] += (dp[i][j][0][0] + dp[i][j][0][1])%mod) %= mod;
            (dp[i][j + 1][1][1] += dp[i][j][0][0]) %= mod;
            (dp[i][j + 1][1][0] += (dp[i][j][1][0] + dp[i][j][1][1])%mod) %= mod;
            (dp[i + 1][j][0][0] += (dp[i][j][1][0] + dp[i][j][1][1])%mod) %= mod;
            (dp[i + 1][j][0][1] += dp[i][j][1][0]) %= mod;
        }
    }
    for(j=0;j<=4000;j++){
        sum[0][j] = 0;
        for(i=0;i + j<=4000;i++){
            sum[i + 1][j] = sum[i][j];
            for(k=0;k<2;k++){
                for(l=0;l<2;l++) (sum[i + 1][j] += dp[i + j][i][k][l]) %= mod;
            }
        }
    }
    int q; cin >> q;
    for(i=0;i<q;i++){
        int x,y; cin >> x >> y;
        if(x<y) swap(x,y);
        ll ans = sum[y + 1][x - y];
        (ans *= (mod + 1)/2) %= mod;
        cout << ans << "\n";
    }
}