#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
const ll ILL=2167167167167167167;
const int INF=2100000000;
const int mod=998244353;
#define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}
template<class T> void vec_out(vector<T> &p,int ty=0){
if(ty==2){cout<<'{';for(int i=0;i<(int)p.size();i++){if(i){cout<<",";}cout<<'"'<<p[i]<<'"';}cout<<"}\n";}
else{if(ty==1){cout<<p.size()<<"\n";}for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}}
template<class T> T vec_min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T vec_max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T vec_sum(vector<T> &a){assert(!a.empty());T ans=a[0]-a[0];for(auto &x:a) ans+=x;return ans;}
int pop_count(long long a){int res=0;while(a){res+=(a&1),a>>=1;}return res;}



template<class T>
using square_matrix=std::vector<std::vector<T>>;
template<class T,T (*add_op)(T,T),T(*add_e)(),T (*mul_op)(T,T),T(*mul_e)()>
square_matrix<T> mul_matrix(square_matrix<T> l,square_matrix<T> r){
	int n=l.size();
	assert((int)l[0].size()==n&&(int)r.size()==n&&(int)r[0].size()==n);
	square_matrix<T> val(n,std::vector<T>(n,add_e()));
	for(int i=0;i<n;i++) for(int j=0;j<n;j++) for(int k=0;k<n;k++){
		val[i][k]=add_op(val[i][k],mul_op(l[i][j],r[j][k]));
	}
	return val;
}
template<class T,T (*add_op)(T,T),T(*add_e)(),T (*mul_op)(T,T),T(*mul_e)()>
square_matrix<T> pow_matrix(square_matrix<T> l,long long times){
	int n=l.size();
	square_matrix<T> val(n,std::vector<T>(n,add_e()));
	for(int i=0;i<n;i++) val[i][i]=mul_e();
	while(times){
		if(times&1){
			val=mul_matrix<T,add_op,add_e,mul_op,mul_e>(val,l);
		}
		l=mul_matrix<T,add_op,add_e,mul_op,mul_e>(l,l);
		times>>=1;
	}
	return val;
}

using mat_F=ll;
mat_F add_op(mat_F a,mat_F b){
	return (a+b)%mod;
}
mat_F add_e(){
	return 0;
}
mat_F mul_op(mat_F a,mat_F b){
	return (a*b)%mod;
}
mat_F mul_e(){
	return 1;
}
#define calc mat_F,add_op,add_e,mul_op,mul_e



void solve();
// oddloop
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    
    int t=1;
    //cin>>t;
    rep(i,0,t) solve();
}

void solve(){
    ll L=10001000;
    vector<ll> dp(L);
    dp[1]=1;
    rep(i,2,L){
        dp[i]+=2ll*dp[i-1]*(i-1)%mod;
        dp[i]+=dp[i-2]*(i-2)%mod;
        dp[i]%=mod;
    }
    int T;
    cin>>T;
    while(T--){
        ll n,m;
        cin>>n>>m;
        if(n>m) swap(n,m);
        if(min(n,m)==0){
            cout<<"1\n";
            continue;
        }
        ll ans=0;
        if(n==m){
            ans=dp[n]*dp[n]%mod;
            ans=ans*n%mod;
            ans+=(dp[n]*dp[n+1]%mod)*2ll*n%mod;
            ans+=dp[n+1]*(n-1)%mod;
            cout<<ans%mod<<"\n";
            continue;
        }
        ll A=dp[n+1],B=n*dp[n]%mod+(2ll*n+1)*dp[n+1]%mod;
        vector<vector<ll>> p={
            {0,n},
            {1,2ll*n+1}
        };
        p=pow_matrix<calc>(p,m-n-1);
        ll X=(A*p[0][0]+B*p[1][0])%mod;
        ll Y=(A*p[0][1]+B*p[1][1])%mod;
        ans+=X*n%mod;
        ans+=Y*2ll*n%mod;
        ans=ans*dp[n]%mod;
        ans+=(Y*dp[n-1]%mod)*(n-1)%mod;
        cout<<ans%mod<<"\n";
    }
}