#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001

struct combi{
	deque<mint> kaijou;
	deque<mint> kaijou_;
	
	combi(int n){
		kaijou.push_back(1);
		for(int i=1;i<=n;i++){
			kaijou.push_back(kaijou[i-1]*i);
		}
		
		mint b=kaijou[n].inv();
		
		kaijou_.push_front(b);
		for(int i=1;i<=n;i++){
			int k=n+1-i;
			kaijou_.push_front(kaijou_[0]*k);
		}
	}
	
	mint combination(int n,int r){
		if(r>n)return 0;
		mint a = kaijou[n]*kaijou_[r];
		a *= kaijou_[n-r];
		return a;
	}
	
	mint junretsu(int a,int b){
		mint x = kaijou_[a]*kaijou_[b];
		x *= kaijou[a+b];
		return x;
	}
	
	mint catalan(int n){
		return combination(2*n,n)/(n+1);
	}
	
};
combi C(300000);

int main(){
	
	int N,M;
	cin>>N>>M;
	M = N*(N-1)/2 - M;
	if(M > N){
		cout<<0<<endl;
		return 0;
	}
	vector dp(N+1,vector<mint>(M+1,0));
	dp[0][0] = 1;
	rep(i,N){
		rep(j,M+1){
			for(int k=1;k<=N;k++){
				int ii = i+k;
				int jj = j+(k-1);
				if(ii>N||jj>M)break;
				if(k==1){
					dp[ii][jj] += dp[i][j];
				}
				else{
					dp[ii][jj] += dp[i][j] * C.combination(N-i-1,k-1) * C.kaijou[k] * C.kaijou_[2];
				}
			}
			for(int k=5;k<=N;k++){
				int ii = i+k;
				int jj = j+k;
				if(ii>N||jj>M)break;
				dp[ii][jj] += dp[i][j] * C.combination(N-i-1,k-1) * C.kaijou[k-1] * C.kaijou_[2];
			}
		}
	}
	/*
	rep(i,N+1){
		rep(j,M+1){
			cout<<dp[i][j].val()<<',';
		}
		cout<<endl;
	}
	*/
	cout<<dp[N][M].val()<<endl;
	
	return 0;
}