#include <iostream>
#include <fstream>
#include <cstdio>
#include <sstream>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <string>
#include <map>
#include <vector>
#include <set>
#include <queue>
#include <deque>
#include <ctime>
#include <cstdlib>

using namespace std;

#define sz(x) ((int)((x).size()))

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;

const double EPS = 1e-9;

const int MOD = (int)(1e9) + 7;

void add(int &x, int y) {
	x += y;
	if (x >= MOD)
		x -= MOD;
}

int binPow(int a, int n) {
	int res = 1;
	while (n > 0) {
		if (n & 1)
			res = res * 1LL * a % MOD;
		n >>= 1;
		a = a * 1LL * a % MOD;
	}
	return res;
}

int n, x;
ll d;
int dp[2050][2050];
int f[2050], rf[2050];

void preCalc() {
	f[0] = 1;
	for (int i = 1; i < 2050; i++) {
		f[i] = f[i - 1] * 1LL * i % MOD;
		rf[i] = binPow(f[i], MOD - 2);
	}
}

void solve() {
	for (int i = 0; i < n + 1; i++) {
		for (int j = 0; j < n + 1; j++) {
			dp[i][j] = 0;
		}
	}
	dp[0][0] = 1;
	int nn = (int)(min(n * 1LL, d));
	for (int i = 0; i < nn; i++) {
		for (int j = 0; j < n; j++) {
			if (dp[i][j] == 0)
				continue;
			for (int k = 1; k < x; k++) {
				if (j + k > n)
					break;
				int cnt = (d - i) % MOD;
				add(dp[i + 1][j + k], dp[i][j] * 1LL * cnt % MOD);
			}
		}
	}
	int ans = 0;
	for (int i = 1; i <= nn; i++) {
		add(ans, dp[i][n] * 1LL * rf[i] % MOD);
	}
	printf("%d\n", ans);
}

int main() {
	//freopen(".in", "r", stdin);
	//freopen(".out", "w", stdout);

	preCalc();
	while (scanf("%d%lld%d", &n, &d, &x) == 3 && n > 0) {
		solve();
	}

	return 0;
}
