#include<bits/stdc++.h>
#define pii pair<ll,ll>
#define x first
#define y second
#define mp(x,y) make_pair(x,y)
#define ep emplace_back
using namespace std;
typedef __int128 ll;
constexpr int mod=998244353;
ll C2(ll n)
{
	return (ll)n*(n-1)/2;
}
ll qpow(ll x,ll y)
{
	ll res=1;
	while(y)
	{
		if(y&1)res=1ll*res*x%mod;
		x=1ll*x*x%mod;
		y>>=1;
	}
	return res;
}
ll sk(ll x)
{
	if(x<0)return 0;
	//cout<<x*(1+x)*x/2<<'-'<<1ll*x*(x+1)*(2*x+1)%mod*qpow(6,mod-2)%mod<<'\n';
	return (1ll*x*(1+x)%mod*x*qpow(2,mod-2)%mod+mod-1ll*x*(x+1)%mod*(2*x+1)%mod*qpow(6,mod-2)%mod)%mod;
}
signed main()
{
	cin.tie(0)->sync_with_stdio(false);
	ll T;int t;
	cin>>t;T=t;
	while(T--)
	{
		ll n,m;int x;
		cin>>x;n=x;
		cin>>x;m=x;
		ll a=4-2*(min(n,m)==1);
		ll b=n+m+n+m-4-a;
		if(min(n,m)==1) b=(n+m-3);
		ll c=n*m-a-b;
		if(n==1&&m==1)
		{
			cout<<1<<'\n';
			continue;
		}
		if(min(n,m)==1)
		{
			cout<<(int)((2+C2((1ll*n*m-2)%mod))%mod)<<'\n';;
			continue;
		}
		ll ans=(c-1)*(c-2)%mod*(c-3)%mod*(c)%mod*qpow(24,mod-2)%mod;
		ans+=4;
		ans+=C2(2*(n-2))+C2((m-2)*2);
		ans=(ans+2ll*(n-2)*2*(m-2)%mod*c)%mod;
		ans+=2*(n-2+m-2)*C2((n-2)*(m-2)%mod)%mod;
		ans=(ans+(mod-1ll)*2%mod*(m-2)*(m-2)%mod*sk(n-5))%mod;
		ans=(ans+(mod-1ll)*2%mod*(n-2)*(n-2)%mod*sk(m-5))%mod;
		cout<<((int)ans)<<'\n';
	}
	return 0;
}