//Author: Kevin
#include<bits/stdc++.h>
//#pragma GCC optimize("O2")
using namespace std;
#define ll long long
#define ull unsigned ll
#define pb emplace_back
#define mp make_pair
#define ALL(x) (x).begin(),(x).end()
#define rALL(x) (x).rbegin(),(x).rend()
#define srt(x) sort(ALL(x))
#define rev(x) reverse(ALL(x))
#define rsrt(x) sort(rALL(x))
#define sz(x) (int)(x.size())
#define inf 0x3f3f3f3f
#define pii pair<int,int>
#define lb(v,x) (int)(lower_bound(ALL(v),x)-v.begin())
#define ub(v,x) (int)(upper_bound(ALL(v),x)-v.begin())
#define uni(v) v.resize(unique(ALL(v))-v.begin())
#define longer __int128_t
void die(string S){puts(S.c_str());exit(0);}
const ll mod=998244353;
struct Matrix
{
	ll val[3][3];
	Matrix(vector<ll> vec)
	{
		for(int i=0;i<3;i++)
			for(int j=0;j<3;j++)
				val[i][j]=vec[i*3+j];
	}
	Matrix(){}
	ll* operator [](int x){return val[x];}
	friend Matrix operator *(Matrix a,Matrix b)
	{
		Matrix ret;
		for(int i=0;i<3;i++)
			for(int j=0;j<3;j++)
				ret[i][j]=0;
		for(int i=0;i<3;i++)
			for(int j=0;j<3;j++)
				for(int k=0;k<3;k++)
					ret[i][j]=(ret[i][j]+a[i][k]*b[k][j])%mod;
		return ret;
	}
};
Matrix ksm(Matrix a,ll b)
{
	Matrix ans({1,0,0,0,1,0,0,0,1});
	while(b)
	{
		if(b&1) ans=ans*a;
		a=a*a;
		b>>=1;
	}
	return ans;
}
Matrix F(ll p,ll q,ll r,ll M,Matrix U,Matrix R)
{
	if(!M) return Matrix({1,0,0,0,1,0,0,0,1});
	if((longer)(p*M+r)<q) return ksm(R,M);
	if(p>=q) return F(p%q,q,r,M,U,ksm(U,p/q)*R);
	return ksm(R,(q-r-1)/p)*U*F(q,p,(q-r-1)%p,(longer)(p*M+r)/q-1,R,U)*ksm(R,M-(longer(p*M-1-(p*M+r)%q)/p));
}
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int t;
	cin>>t;
	while(t--)
	{
		ll A,B;
		cin>>A>>B;
		Matrix U=Matrix({1,0,0,1,1,0,1,0,1}),R=Matrix({1,1,0,0,1,0,0,1,1});
		Matrix ans=U*R*F(A,B,0,B-1,U,R);
		ll tot=A+B-(B-1)-2-(B-1)*A/B;
		ans=ans*ksm(U,tot);
		cout<<(ans[2][0]+ans[2][1]+ans[2][2])%mod<<endl;
	}
	return 0;
}