#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myRand(ll B) {
    return (ull)rng() % B;
}
inline double time() {
    return static_cast<long double>(chrono::duration_cast<chrono::nanoseconds>(chrono::steady_clock::now().time_since_epoch()).count()) * 1e-9;
}

template <int mod>
struct static_modint {
    using mint = static_modint;
    int x;

    static_modint() : x(0) {}
    static_modint(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}

    mint& operator+=(const mint& rhs) {
        if ((x += rhs.x) >= mod) x -= mod;
        return *this;
    }
    mint& operator-=(const mint& rhs) {
        if ((x += mod - rhs.x) >= mod) x -= mod;
        return *this;
    }
    mint& operator*=(const mint& rhs) {
        x = (int) (1LL * x * rhs.x % mod);
        return *this;
    }
    mint& operator/=(const mint& rhs) { return *this = *this * rhs.inv(); }

    mint pow(long long n) const {
        mint _x = *this, r = 1;
        while (n) {
            if (n & 1) r *= _x;
            _x *= _x;
            n >>= 1;
        }
        return r;
    }
    mint inv() const { return pow(mod - 2); }

    mint operator+() const { return *this; }
    mint operator-() const { return mint() - *this; }
    friend mint operator+(const mint& lhs, const mint& rhs) {
        return mint(lhs) += rhs;
    }
    friend mint operator-(const mint& lhs, const mint& rhs) {
        return mint(lhs) -= rhs;
    }
    friend mint operator*(const mint& lhs, const mint& rhs) {
        return mint(lhs) *= rhs;
    }
    friend mint operator/(const mint& lhs, const mint& rhs) {
        return mint(lhs) /= rhs;
    }
    friend bool operator==(const mint& lhs, const mint& rhs) {
        return lhs.x == rhs.x;
    }
    friend bool operator!=(const mint& lhs, const mint& rhs) {
        return lhs.x != rhs.x;
    }

    friend ostream &operator<<(ostream &os, const mint &p) {
        return os << p.x;
    }
    friend istream &operator>>(istream &is, mint &a) {
        int64_t t; is >> t;
        a = static_modint<mod>(t);
        return (is);
    }
};

const unsigned int mod = 998244353;
using modint = static_modint<mod>;
modint mod_pow(ll n, ll x) { return modint(n).pow(x); }
modint mod_pow(modint n, ll x) { return n.pow(x); }

template <typename T>
struct Comination {
    vector<T> p, invp;

    Comination(int sz) : p(sz+1), invp(sz+1) {
        p[0] = 1;
        for (int i = 1; i <= sz; ++i) {
            p[i] = p[i-1] * i;
        }
        invp[sz] = p[sz].inv();
        for (int i = sz-1; i >= 0; --i) {
            invp[i] = invp[i+1] * (i+1);
        }
    }

    T comb(int n, int r) {
        if (r < 0 or n < r) return 0;
        return p[n]*invp[n-r]*invp[r];
    }
    T big_comb(T n, int r) {
        T res = invp[r];
        for (int i = 0; i < r; ++i) {
            res *= (n-i);
        }
        return res;
    }
};
using Comb = Comination<modint>;
Comb p(1<<20);

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int q; cin >> q;
    while (q--) {
        ll n,k; cin >> n >> k;
        // x+y = n
        // (x+1)y = k
        // (x+1)(n-x) = k
        // -x^2+(n-1)x+n-k = 0
        // x^2-(n-1)x+k-n = 0

        ll b = -(n-1), c = k-n;
        ll d = b*b - 4*c;
        auto sq = [](ll x) -> ll {
            ll s = sqrt(abs(x));
            for (int i = -2; i <= 2; ++i) {
                if ((s+i)*(s+i) == x) return abs(s+i);
            }
            return 0;
        };
        if (d < 0) {
            cout << 0 << "\n";
            continue;
        }
        ll s = sq(d);
        if (s*s != d) {
            cout << 0 << "\n";
            continue;
        }
        ll x1 = (-b+s)/2;
        ll x2 = (-b-s)/2;

        modint res = 0;
        if (x1 >= 0 and (x1+1)*(n-x1) == k) {
            res += p.comb(n, x1);
        }
        if (x2 >= 0 and x2 != x1 and (x2+1)*(n-x2) == k) {
            res += p.comb(n, x2);
        }
        cout << res << "\n";
    }
}