#include <bits/stdc++.h>
using namespace std;
int dp[105][2];
int main() {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  memset(dp, 0, sizeof dp);
  int n, k, d;
  cin >> n >> k >> d;
  dp[0][0] = 1;
  for (int i = 1; i <= n; ++i) {
    for (int j = 1; j <= k && i >= j; ++j) {
      if (j < d)
        dp[i][0] =
            (dp[i][0] % 1000000007 + dp[i - j][0] % 1000000007) % 1000000007;
      dp[i][1] =
          (dp[i][1] % 1000000007 + dp[i - j][1] % 1000000007) % 1000000007;
      if (j >= d)
        dp[i][1] =
            (dp[i][1] % 1000000007 + dp[i - j][0] % 1000000007) % 1000000007;
    }
  }
  cout << dp[n][1] << endl;
  return 0;
}
