#include<iostream>
#include<vector>
#include<atcoder/modint>
using namespace std;
using mint = atcoder::modint998244353;

int main(){
    int maxN = 1000000;
    vector DP(maxN+1,vector<mint>(10,0));
    vector<mint> power2(maxN+2,2);
    for(int i = 1; i <= maxN+1; i++)power2[i] = power2[i-1] * power2[i-1];

    DP[2] = {5,2,1,0,0,0,0,0,0,0};
    for(int i = 3; i <= maxN; i++){
        DP[i][0] = power2[i]/4;
        for(int from1 = 0; from1 < 10; from1++){
            for(int from2 = 0; from2 < 10; from2++){
                if(from1 + from2 > 9)break;
                DP[i][from1 + from2] += DP[i-1][from1] * DP[i-1][from2];
            }
        }
    }

    int T;
    cin >> T;
    for(int testcase = 0; testcase < T; testcase++){
        int N,K;
        cin >> N >> K;
        cout << DP[N][K-1].val() << endl;
    }
    return 0;
}