#include <bits/stdc++.h>
using namespace std;

int main()
{
    int n,d,k;
    cin >> n >> d >> k;

    vector<vector<long long>> dp(n + 1, vector<long long>(k + d + 10,0));

    dp[0][0] = 1;//配るDP
    for (int i = 1; i < n + 1; i++)
    {
        long long sumdp[k + 1] = {0};
        for (int j = 0; j <= k; j++)
        {
            sumdp[j + 1] = sumdp[j] + dp[i - 1][j];
        }
        for (int j = 0; j <= k; j++)
        {
            if(j < d)
            {
                dp[i][j] = sumdp[j] - sumdp[0];
            }
            else
            {
                dp[i][j] = sumdp[j] - sumdp[j - d];
            }
            
        }
    }
    
    //for (int i = 0; i < n + 1; i++){for (int j = 0; j < k + d + 10; j++){cout << dp[i][j] << " ";}cout << endl;}
    
    cout << dp[n][k] << endl;
}