#include<bits/stdc++.h>
using namespace std;
int test,n,m,fac[200010],inv[100010],inve[100010];
const int P=998244353;
int main()
{
	scanf("%d",&test);
	for(;test--;)
	{
		scanf("%d%d",&n,&m);
		fac[0]=fac[1]=inv[1]=inve[0]=inve[1]=1;
		for(int i=2;i<=n;i++)
		{
			fac[i]=1LL*fac[i-1]*i%P;
			inv[i]=1LL*(P-P/i)*inv[P%i]%P;
			inve[i]=1LL*inve[i-1]*inv[i]%P;
		}
		int sum=0;
		for(int i=0;i<m;i++) sum=(sum+1LL*fac[n-1]*inve[i]%P*inve[n-i-1]%P)%P;
		int ans=1;
		for(int i=1;i<=n;i++) ans=ans*2%P;
		ans=(ans-1+P)%P;
		printf("%lld\n",1LL*sum*ans%P);
	}
	return 0;
}