def f(step,count):
    if count==0:
        if step==0:
            return 1
        else:
            return 0

    if not count<=step<=d*count:
        return 0

    if (step,count) in Memo:
        return Memo[(step,count)]

    X=0
    for x in range(1,d+1):
        X+=f(step-x,count-1)
    X%=Mod

    Memo[(step,count)]=X
    return X

N,d,K=map(int,input().split())
Mod=10**9+7
Memo={}
print(f(K,N))