#include <bits/stdc++.h>
#define rep(i,j,k) for(int i=(j);i<=(k);i++)
#define per(i,j,k) for(int i=(j);i>=(k);i--)
#define uint unsigned int
#define ll long long
#define ull unsigned long long
#define db double
#define ldb long double
#define pii pair<int,int>
#define pll pair<ll,ll>
#define mkp make_pair
#define eb emplace_back
#define SZ(S) (int)S.size()
#define mod 998244353
//#define mod 1000000007
#define inf 0x3f3f3f3f
#define linf 0x3f3f3f3f3f3f3f3f
using namespace std;

template <class T>
void chkmax(T &x,T y){
    if(x < y) x = y;
}

template <class T>
void chkmin(T &x,T y){
    if(x > y) x = y;
}

inline int popcnt(int x){
    return __builtin_popcount(x);
}

inline int ctz(int x){
    return __builtin_ctz(x);
}

template <int P>
class mod_int
{
    using Z = mod_int;

private:
    static int mo(int x) { return x < 0 ? x + P : x; }

public:
    int x;
    int val() const { return x; }
    mod_int() : x(0) {}
    template <class T>
    mod_int(const T &x_) : x(x_ >= 0 && x_ < P ? static_cast<int>(x_) : mo(static_cast<int>(x_ % P))) {}
    bool operator==(const Z &rhs) const { return x == rhs.x; }
    bool operator!=(const Z &rhs) const { return x != rhs.x; }
    Z operator-() const { return Z(x ? P - x : 0); }
    Z pow(long long k) const
    {
        Z res = 1, t = *this;
        while (k)
        {
            if (k & 1)
                res *= t;
            if (k >>= 1)
                t *= t;
        }
        return res;
    }
    Z &operator++()
    {
        x < P - 1 ? ++x : x = 0;
        return *this;
    }
    Z &operator--()
    {
        x ? --x : x = P - 1;
        return *this;
    }
    Z operator++(int)
    {
        Z ret = x;
        x < P - 1 ? ++x : x = 0;
        return ret;
    }
    Z operator--(int)
    {
        Z ret = x;
        x ? --x : x = P - 1;
        return ret;
    }
    Z inv() const { return pow(P - 2); }
    Z &operator+=(const Z &rhs)
    {
        (x += rhs.x) >= P && (x -= P);
        return *this;
    }
    Z &operator-=(const Z &rhs)
    {
        (x -= rhs.x) < 0 && (x += P);
        return *this;
    }
    Z operator-()
    {
        return -x;
    }
    Z &operator*=(const Z &rhs)
    {
        x = 1ULL * x * rhs.x % P;
        return *this;
    }
    Z &operator/=(const Z &rhs) { return *this *= rhs.inv(); }
#define setO(T, o)                                  \
    friend T operator o(const Z &lhs, const Z &rhs) \
    {                                               \
        Z res = lhs;                                \
        return res o## = rhs;                       \
    }
    setO(Z, +) setO(Z, -) setO(Z, *) setO(Z, /)
#undef setO
    
    friend istream& operator>>(istream& is, mod_int& x)
    {
        long long tmp;
        is >> tmp;
        x = tmp;
        return is;
    }
    friend ostream& operator<<(ostream& os, const mod_int& x)
    {
        os << x.val();
        return os;
    }
};

using Z = mod_int<mod>;
Z power(Z p,ll k){
    Z ans = 1;
    while(k){
        if(k % 2 == 1) ans *= p;
        p *= p;
        k /= 2;
    }
    return ans;
}
Z CC(ll n,int m){
    Z answer = 1;
    rep(i,1,m) answer *= n + 1 - i;
    rep(i,1,m) answer /= i;
    return answer;
}

Z fix2o(int n,int m){
    return CC(2 * (n - 2),2);
}

Z fix2(int n,int m){
    return fix2o(n,m) + fix2o(m,n);
}

Z fixo(int n,int m){
    Z temp = CC(2 * (n - 2),2) * Z(1ll * n * (m - 2));
    temp += CC(2 * (n - 2),3);
    return temp;
}

Z fix(int n,int m){
    return fixo(n,m) + fixo(m,n);
}

const Z i6 = Z(1) / 6;
Z fix3o(int n,int m){
    n -= 6;
    if(n < 0) return 0;
    Z answer = 0;
    answer += CC(n + 1,2) * (n + 1) - Z(n) * (n + 1) * (2 * n + 1) * i6;
    answer *= 2 * Z(m - 2) * Z(m - 2);
    return answer;
}

Z fix3(int n,int m){
    return fix3o(n,m) + fix3o(m,n);
}
int T,n,m;

void solve(){
    scanf("%d%d",&n,&m);
    if(m == 1) swap(n,m);
    if(n == 1){
        if(m == 1){
            printf("1\n");
            return;
        }
        printf("%d\n",(CC(m - 2,2) + 2).val());
        return;
    }
    Z answer = CC(1ll * (n - 2) * (m - 2),4);
    answer += CC(1ll * n * m - 4,3) - CC(1ll * (n - 2) * (m - 2),3) - fix(n,m) - fix3(m,n);
//    printf("%d %d %d\n",answer.val(),CC(1ll * n * m - 4,3).val(),fix(n,m).val());
    answer += fix2(n,m);
    answer += 4;
    printf("%d\n",answer.val());
}

int main(){
#ifdef cxy
    freopen("test.in","r",stdin);
#endif
    scanf("%d",&T);
    while(T--) solve();
	return 0;
}