#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 fact[1000005],ifac[1000005],inv[1000005];

Z C(int N,int M){
    if(N < M || M < 0) return 0;
    return fact[N] * ifac[M] * ifac[N - M];
}

void init(int L){
    fact[0] = 1;
    rep(i,1,L) fact[i] = fact[i - 1] * i;
    ifac[L] = 1 / fact[L];
    per(i,L - 1,0) ifac[i] = ifac[i + 1] * (i + 1);
    rep(i,1,L) inv[i] = ifac[i] * fact[i - 1];
}
int T;
Z result[200005],D[200005];

struct qry{
    int p,q,id;
};
const int B = 450,V = 200000;
inline int from(int x){
    return (x + B - 1) / B;
}
inline int L(int x){
    return x * B - B + 1;
}
vector <qry> Q[4005];
bool cmp(qry _a,qry _b){
    return _a.q < _b.q;
}

int n,m;
Z x,y;
void addn(){
    x = C(m,n + 2) + (n + 1) * (x + y) - m * x;
    swap(x,y);
    n++;
}

void subn(){
    n--;
    y = (y - C(m,n + 2) + (m - n - 1) * x) * inv[n + 1];
    swap(x,y); 
}

void addm(){
    Z temp = (y - m * x - C(m,n + 1)) * inv[n - m];
    y = x + y;
    x = temp;
    m++;
}

int main(){
//    freopen("test.in","r",stdin);
    scanf("%d",&T);
    init(V);
    D[0] = 1;D[1] = 0;
    rep(i,2,V) D[i] = (i - 1) * (D[i - 1] + D[i - 2]);
    rep(i,1,T){
        int p,q;
        scanf("%d%d",&p,&q);
        p -= q;
        if(p < q) continue;
        Q[from(p)].push_back({p,q,i});
//        printf("%d %d\n",p,q);
    }
    rep(p,1,from(V)){
        n = L(p);m = 0;
        x = D[n];y = D[n + 1];
        sort(Q[p].begin(),Q[p].end(),cmp);

        for(qry cur:Q[p]){
            while(n < cur.p) addn();
            while(n > cur.p) subn();
            while(m < cur.q) addm();
//            printf("%d %d %d %d\n",n,m,x.val(),y.val());
            result[cur.id] = x * fact[cur.p] * ifac[cur.p - cur.q];
        }
    }
    rep(i,1,T) printf("%d\n",result[i].val());
	return 0;
}