#include <string.h>
#include <algorithm>
#include <array>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <memory>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>
using namespace std;

constexpr int mod = 998244353;

void mpl(int &x,int y) {
    x += y;
    if(x >= mod) x -= mod;
}

vector<vector<int>> Mul(vector<vector<int>> A,vector<vector<int>> B) {
    vector<vector<int>>ans(A.size(),vector<int>(A.size()));
    for(int i = 0; i < A.size(); i++) {
        for(int j = 0; j < A.size(); j++) {
            for(int k = 0; k < A.size(); k++) {
                ans[i][j] += 1ll*A[i][k]*B[k][j]%mod;
                if(ans[i][j] >= mod) ans[i][j] -= mod;
            }
        }
    }
    return ans;
}

vector<vector<int>> Pow(vector<vector<int>> A,long long B,int a,int b) {
    vector<vector<int>>ans(A.size(),vector<int>(A.size()));
    for(int i = 0; i < A.size(); i++) {
        ans[i][i] = 1;
    }
    ans[0][0] = a;
    ans[1][1] = b;
    while (B) {
        if(1 & B) {
            ans = Mul(ans,A);
        }
        A = Mul(A,A);
        B /= 2;
    }
    return ans;
}

int dp[10010010];

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int t;
    cin >> t;
    dp[0] = 1;
    for(int i = 0; i <= 10000000; i++) {
        mpl(dp[i+1],2ll*dp[i]*(i+1)%mod);
        mpl(dp[i+2],1ll*dp[i]*(i+1)%mod);
    }
    while(t--) {
        long long n,m;
        cin >> n >> m;
        if(n > m) {
            swap(n,m);
        }
        if(n == 0) {
            cout << 1 << "\n";
            continue;
        }
        if(n == m) {
            cout << (1ll*dp[n]*dp[n]%mod+1ll*dp[n-1]*dp[n-1]%mod*n%mod)%mod << "\n";
            continue;
        }
        vector<vector<int>>res(2,vector<int>(2));
        res[0][0] = 2*n+1;
        res[0][1] = n;
        res[1][0] = 1;
        res = Pow(res,m-n,dp[n],1ll*dp[n-1]*n%mod);
        cout << (1ll*(res[0][0]+res[1][0])*dp[n]%mod+1ll*(res[0][1]+res[1][1])*dp[n-1]%mod)%mod << "\n";
    }
}