#include <bits/stdc++.h>
using namespace std;
long long dp[101][2];
long long solve(long long n, long long k, long long d, long long inc) {
  if (n < 0) {
    return 0;
  }
  if (n == 0 && (inc == 1 || d == 1)) {
    return 1;
  }
  if (dp[n][inc] != -1) {
    return dp[n][inc];
  }
  long long ans = 0;
  for (long long i = 1; i <= k; i++) {
    long long curinc = inc;
    if (i >= d) {
      curinc = 1;
    }
    ans += solve(n - i, k, d, curinc);
    ans = ans % 1000000007;
  }
  return dp[n][inc] = ans;
}
int32_t main() {
  long long n, k, d;
  cin >> n >> k >> d;
  if (d > n) {
    cout << 0 << endl;
    return 0;
  }
  if (n == d) {
    cout << 1 << endl;
    return 0;
  }
  memset(dp, -1, sizeof(dp));
  cout << solve(n, k, d, 0) << endl;
}
