#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

mint cal[305][305][630];

int main(){
	
	int c = 315;
	rep(i,305){
		vector<mint> dp(630,0);
		dp[c] = 1;
		rep(j,i){
			vector<mint> ndp(630,0);
			rep(k,630){
				ndp[k] += dp[k];
				if(k!=629)ndp[k+1] += dp[k];
			}
			swap(dp,ndp);
		}
		vector<mint> tdp = dp;
		rep(j,305){
			rep(k,630){
				cal[i][j][k] += dp[k];
			}
			vector<mint> ndp(630,0);
			rep(k,630){
				ndp[k] += dp[k];
				if(k!=0)ndp[k-1] += dp[k];
			}
			swap(dp,ndp);
			
		}
		dp = tdp;
	}
	
	
	
	int N,M;
	cin>>N>>M;
	
	vector<int> a(N),b(N);
	rep(i,N)cin>>a[i];
	rep(i,N)cin>>b[i];
	
	queue<pair<vector<mint>,int>> Q;
	rep(i,M){
		vector<mint> t(630,1);
		rep(j,630){
			for(int k=i;k<N;k+=M){
				t[j] *= cal[a[k]][b[k]][j];
			}
		}
		Q.emplace(t,c);
	}
	//cout<<"A"<<endl;
	while(Q.size()>1){
		auto x = Q.front();
		Q.pop();
		auto y = Q.front();
		Q.pop();
		Q.emplace(convolution(x.first,y.first),x.second+y.second);
	}
	
	cout<<Q.front().first[Q.front().second].val()<<endl;
	
	return 0;
}