import sys
def MI(): return map(int,sys.stdin.readline().rstrip().split())


def factorial(N, p):  # 0!~N!(mod p) のリスト
    res = [0] * (N + 1)
    res[0] = 1
    for i in range(1, N + 1):
        res[i] = (res[i - 1] * i) % p
    return res


def factorial_inverse(N, p):  # 0!~N!(mod p) の逆元のリスト
    fac = factorial(N, p)
    res = [0] * (N + 1)
    a = pow(fac[-1], p - 2, p)
    for i in range(N, -1, -1):
        res[i] = a
        a *= i
        a %= p
    return fac, res


N,d,K = MI()
mod = 10**9+7
fac,fac_inv = factorial_inverse(max(N,K-1),mod)


def nCr(n,r):
    if n < r:
        return 0
    return (fac[n]*fac_inv[r]*fac_inv[n-r]) % mod


ans = 0
for i in range(N+1):
    a = nCr(N,i)*nCr(K-1-d*i,N-1)
    a %= mod
    if i % 2:
        ans -= a
    else:
        ans += a
    ans %= mod

print(ans)