#include <bits/stdc++.h>
#define FOR(i, a, n) for(ll i = (ll)a; i < (ll)n; i++)
#define FORR(i, n) for(ll i = (ll)n - 1LL; i >= 0LL; i--)
#define rep(i, n) FOR(i, 0, n)
#define ALL(x) (x).begin(), (x).end()
using namespace std;
using ll = long long;
template <typename T> using V = vector<T>;

constexpr int Mod = 998244353;
constexpr int mod = 1e9 + 7;
constexpr ll inf = 1LL << 60;

template <typename T> constexpr bool chmax(T &a, const T &b) {
    if(a >= b) return false;
    a = b;
    return true;
}
template <typename T> constexpr bool chmin(T &a, const T &b) {
    if(a <= b) return false;
    a = b;
    return true;
}

/*-------------------------------------------*/

int main() {
    cin.tie(0);
    ios::sync_with_stdio(0);

    int n, d, k;
    cin >> n >> d >> k;
    int dp[n + 1][k + 1] = {};
    dp[0][0] = 1;
    rep(i, n) rep(j, k) {
        for(int x = j; x++ < j + d && x <= k;) {
            dp[i + 1][x] += dp[i][j];
        }
    }
    cout << dp[n][k] << endl;

    return 0;
}