#include<bits/stdc++.h>

using namespace std;

using ll = long long;
using ld = long double;
using ull = unsigned long long;

using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pld = pair<ld, ld>;

#define fi first
#define se second
#define left BAO
#define right ANH
#define pb push_back
#define pf push_front
#define mp make_pair
#define ins insert
#define btpc __builtin_popcount
#define btclz __builtin_clz

#define sz(x) (int)(x.size());
#define all(x) x.begin(), x.end()
#define debug(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int d4x[4] = {1, 0, -1, 0}; int d4y[4] = {0, 1, 0, -1};
int d8x[8] = {0, 1, 1, 1, 0, -1, -1, -1};
int d8y[8] = {1, 1, 0, -1, -1, -1, 0, 1};

template<class X, class Y>
    bool minimize(X &x, const Y &y) {
        if (x > y)
        {
            x = y;
            return true;
        }
        return false;
    }
template<class X, class Y>
    bool maximize(X &x, const Y &y) {
        if (x < y)
        {
            x = y;
            return true;
        }
        return false;
    }

const int MOD = 998244353; //998244353

template<class X, class Y>
    void add(X &x, const Y &y) {
        x = (x + y);
        if(x >= MOD) x -= MOD;
    }

template<class X, class Y>
    void sub(X &x, const Y &y) {
        x = (x - y);
        if(x < 0) x += MOD;
    }

/* Author : Le Ngoc Bao Anh, 12A5, LQD High School for Gifted Student*/

const ll INF = 1e9;
const int N = 105;

template <typename T> T mod_inv_in_range(T a, T m) {
    // assert(0 <= a && a < m);
    T x = a, y = m;
    T vx = 1, vy = 0;
    while (x) {
        T k = y / x;
        y %= x;
        vy -= k * vx;
        std::swap(x, y);
        std::swap(vx, vy);
    }
    assert(y == 1);
    return vy < 0 ? m + vy : vy;
}

template <typename T> T mod_inv(T a, T m) {
    a %= m;
    a = a < 0 ? a + m : a;
    return mod_inv_in_range(a, m);
}

template <int MOD_> struct modnum {
    static constexpr int MOD = MOD_;
    static_assert(MOD_ > 0, "MOD must be positive");

    using ll = long long;

    int v;

public:

    modnum() : v(0) {}
    modnum(ll v_) : v(int(v_ % MOD)) { if (v < 0) v += MOD; }
    explicit operator int() const { return v; }
    friend std::ostream& operator << (std::ostream& out, const modnum& n) { return out << int(n); }
    friend std::istream& operator >> (std::istream& in, modnum& n) { ll v_; in >> v_; n = modnum(v_); return in; }

    friend bool operator == (const modnum& a, const modnum& b) { return a.v == b.v; }
    friend bool operator != (const modnum& a, const modnum& b) { return a.v != b.v; }

    modnum inv() const {
        modnum res;
        res.v = mod_inv_in_range(v, MOD);
        return res;
    }
    friend modnum inv(const modnum& m) { return m.inv(); }
    modnum neg() const {
        modnum res;
        res.v = v ? MOD-v : 0;
        return res;
    }
    friend modnum neg(const modnum& m) { return m.neg(); }

    modnum operator- () const {
        return neg();
    }
    modnum operator+ () const {
        return modnum(*this);
    }

    modnum& operator ++ () {
        v ++;
        if (v == MOD) v = 0;
        return *this;
    }
    modnum& operator -- () {
        if (v == 0) v = MOD;
        v --;
        return *this;
    }
    modnum& operator += (const modnum& o) {
        v -= MOD-o.v;
        v = (v < 0) ? v + MOD : v;
        return *this;
    }
    modnum& operator -= (const modnum& o) {
        v -= o.v;
        v = (v < 0) ? v + MOD : v;
        return *this;
    }
    modnum& operator *= (const modnum& o) {
        v = int(ll(v) * ll(o.v) % MOD);
        return *this;
    }
    modnum& operator /= (const modnum& o) {
        return *this *= o.inv();
    }

    friend modnum operator ++ (modnum& a, int) { modnum r = a; ++a; return r; }
    friend modnum operator -- (modnum& a, int) { modnum r = a; --a; return r; }
    friend modnum operator + (const modnum& a, const modnum& b) { return modnum(a) += b; }
    friend modnum operator - (const modnum& a, const modnum& b) { return modnum(a) -= b; }
    friend modnum operator * (const modnum& a, const modnum& b) { return modnum(a) *= b; }
    friend modnum operator / (const modnum& a, const modnum& b) { return modnum(a) /= b; }
};
using num = modnum<MOD>;

num f[N], invf[N];
int w[N], v[N];
num dp[N][N][N], combi[N][N];

num power(num a, ll b) {
    if(b == 0) return 1;
    num ans = power(a, b / 2);
    ans = ans * ans;
    if(b & 1) ans = ans * a;
    return ans;
}


void BaoJiaoPisu() {
    int n, we, k; cin >> n >> we >> k;
    for(int i = 1; i <= n; i++) cin >> w[i] >> v[i];

    f[0] = 1;
    for(int i = 1; i <= k; i++) f[i] = f[i - 1] * i;
    invf[k] = 1 / f[k];
    for(int i = k - 1; i >= 0; i--) invf[i] = invf[i + 1] * (i + 1);

    auto C = [&](int n, int k) -> num {
        //n is very high, but k is small (<= 100);
        if(n < k || k < 0) return 0;

        num ans = 1;
        for(int i = n; i > n - k; i--) ans *= i;
        ans *= invf[k];
        return ans;
    };

    auto S = [&](int n, int k) -> num {
        //Stirling number of the second kind
        if(n < k || k < 0) return 0;
        num ans = 0;
        for(int i = 0; i <= k; i++) {
            if(i & 1) ans -= C(k, i) * power(k - i, n);
            else ans += C(k, i) * power(k - i, n);
        }

        ans /= f[k];
        return ans;
    };

     //n ^ k = sigma(i : 0 -> k) S(k, i) * C(n, i) * i!

    dp[0][0][0] = 1;
    //precalculate combi

    for(int i = 1; i <= n; i++) {
        for(int j = 0; j <= k; j++) {
            combi[i][j] = C(v[i], j);
        }
    }

    //dp[index][weight][combi]

    for(int i = 0; i < n; i++) {
        for(int j = 0; j <= we; j++) {
            for(int x = 0; x <= k; x++) {
                dp[i + 1][j][x] += dp[i][j][x];
                if(j + w[i + 1] <= we) {
                    for(int y = 0; y <= k - x; y++) {
                        dp[i + 1][j + w[i + 1]][x + y] += dp[i][j][x] * combi[i + 1][y];
                    }
                }
            }
        }
    }

    num ans = 0;
    for(int i = 0; i <= k; i++) {
        num Stirling = S(k, i);
        for(int j = 0; j <= we; j++) {
            ans += Stirling * f[i] * dp[n][j][i];
        }
    }

    cout << ans;
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #else
    //online
    #endif

    int tc = 1, ddd = 0;
    // cin >> tc;
    while(tc--) {
        //ddd++;
        //cout << "Case #" << ddd << ": ";
        BaoJiaoPisu();
    }
}