#include <bits/stdc++.h>
using namespace std;
const long long HALF = 499122177;
const long long MOD = 998244353;
int main(){
  int N, M;
  cin >> N >> M;
  M = N * (N - 1) / 2 - M;
  if (M > N){
    cout << 0 << endl;
  } else {
    vector<long long> fact(N + 1);
    fact[0] = 1;
    for (int i = 1; i <= N; i++){
      fact[i] = fact[i - 1] * i % MOD;
    }
    vector<vector<long long>> binom(N + 1, vector<long long>(N + 1, 0));
    for (int i = 0; i <= N; i++){
      binom[i][0] = 1;
      for (int j = 1; j < i; j++){
        binom[i][j] = (binom[i - 1][j - 1] + binom[i - 1][j]) % MOD;
      }
      binom[i][i] = 1;
    }
    vector<vector<long long>> dp(N + 1, vector<long long>(M + 1, 0));
    dp[0][0] = 1;
    for (int i = 0; i < N; i++){
      for (int j = 0; j <= M; j++){
        for (int k = 5; k <= N - i; k++){
          if (j + k <= M){
            dp[i + k][j + k] += dp[i][j] * binom[N - i - 1][k - 1] % MOD * fact[k - 1] % MOD * HALF % MOD;
            dp[i + k][j + k] %= MOD;
          }
        }
        for (int k = 2; k <= N - i; k++){
          if (j + k - 1 <= M){
            dp[i + k][j + k - 1] += dp[i][j] * binom[N - i - 1][k - 1] % MOD * fact[k] % MOD * HALF % MOD;
            dp[i + k][j + k - 1] %= MOD;
          }
        }
        dp[i + 1][j] += dp[i][j];
        dp[i + 1][j] %= MOD;
      }
    }
    cout << dp[N][M] << endl;
  }
}