#include <bits/stdc++.h>

#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define RFOR(i, a, b) for (int i = (b)-1; i >= (a); i--)
#define rep(i, n) for (int i = 0; i < (n); i++)
#define rep1(i, n) for (int i = 1; i <= (n); i++)
#define rrep(i, n) for (int i = (n)-1; i >= 0; i--)

#define pb push_back
#define mp make_pair
#define fst first
#define snd second
#define show(x) cout << #x << " = " << x << endl
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define pii pair<int, int>
#define vi vector<int>

using namespace std;
template <class S, class T>
ostream& operator<<(ostream& o, const pair<S, T>& p)
{
    return o << "(" << p.first << "," << p.second << ")";
}
template <class T>
ostream& operator<<(ostream& o, const vector<T>& vc)
{
    o << "sz = " << vc.size() << endl
      << "[";
    for (const T& v : vc)
        o << v << ",";
    o << "]";
    return o;
}
using ll = long long;
constexpr ll MOD = 1000000007;

constexpr int MAX_N = 101;
constexpr int MAX_S = 20001;

ll dp[MAX_N][MAX_S];

int main()
{
    ll N, S, K;
    cin >> N >> S >> K;
    rep(i, (S / N) + 1)
    {
        dp[1][N * i] = 1;
    }
    FOR(n, 2, N + 1)
    {
        FOR(s, (N - n + 1) * K, S + 1)
        {
            if (s >= (N - n + 1)) {
                dp[n][s] = (dp[n - 1][s - K * (N - n + 1)] + dp[n][s - (N - n + 1)]) % MOD;
            } else {
                dp[n][s] = dp[n - 1][s - K * (N - n + 1)];
            }
        }
    }

    cout << dp[N][S] << endl;

    return 0;
}