#include <iostream>

using namespace std;
typedef long long ll;
ll mod = 998244353;
ll pw(ll a,ll x){
    ll ret = 1;
    while(x){
        if(x&1) (ret *= a) %= mod;
        (a *= a) %= mod; x /= 2;
    }
    return ret;
}

int main(){
    int t; cin >> t;
    while(t){
        t--;
        ll n,k; cin >> n >> k;
        cout << n*((pw(2,n*k) - pw(2,k*(n - 1)) + mod)%mod)%mod << endl;
    }
}