#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int n, k, d;
  cin >> n >> k >> d;
  long long a[101], b[101];
  memset(a, 0, sizeof(a));
  memset(b, 0, sizeof(b));
  a[0] = 1;
  long long sum = 0;
  for (int i = 0; i < k; i++) {
    sum += a[i];
    sum = (sum) % 1000000007;
    a[i + 1] = sum;
  }
  for (int i = k; i < n; i++) {
    sum += a[i];
    sum -= a[i - k];
    sum = ((sum % 1000000007) + 1000000007) % 1000000007;
    a[i + 1] = sum;
  }
  for (int i = 1; i < d; i++) {
    b[i] = 0;
  }
  b[d] = 1;
  for (int i = d + 1; i <= k; i++) {
    b[i] = b[i - 1] + b[i - 1] - b[i - d] + a[i - d];
    b[i] = ((b[i] % 1000000007) + 1000000007) % 1000000007;
  }
  for (int i = k + 1; i <= n; i++) {
    b[i] = b[i - 1] + b[i - 1] - b[i - d] + a[i - d] - a[i - k - 1];
    b[i] = ((b[i] % 1000000007) + 1000000007) % 1000000007;
  }
  cout << b[n] << endl;
}
