#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<ll,ll> P;
#define REP(i,n) for(ll i=0;i<ll(n);i++)







const ll MOD=998244353;
ll f(ll x,ll n){
    ll res=1;
    while(n!=0LL){
	if(n%2!=0LL) res=(res*x)%MOD;
	x=(x*x)%MOD;
	n/=2;
   }
    return res;
}











int main(void){
	cin.tie(nullptr);  ios_base::sync_with_stdio(false);
	ll i,j;




	int T;
	cin >> T;
	while(T--){


		ll N,M;
		cin >> N >> M;

		ll x=(f(2,N)-1+MOD)%MOD;
		x=f(x,M);
		ll y=f(2,N*M);
		ll z=(f(2,M)-1+MOD)%MOD;
		z=f(z,N);


		cout << (x-y+MOD+z)%MOD << endl;






	}











	return 0;

}