#include <bits/stdc++.h>
using namespace std;
int n, d, k;
long long int dp[150][2];
int main() {
  scanf("%d%d%d", &n, &k, &d);
  dp[0][0] = 1;
  dp[0][1] = 0;
  for (int i = 1; i <= n; i++) {
    dp[i][0] = dp[i][1] = 0;
    for (int j = 1; j <= k; j++) {
      if (i - j < 0) break;
      if (j < d) {
        dp[i][0] += dp[i - j][0] % 1000000007;
        dp[i][1] += dp[i - j][1] % 1000000007;
      } else {
        dp[i][1] += dp[i - j][0] % 1000000007;
        dp[i][1] += dp[i - j][1] % 1000000007;
      }
    }
  }
  std::cout << dp[n][1] % 1000000007 << std::endl;
}
