N,d,K=map(int,input().split())
L=[[0 for K in range(K)] for i in range(N)]
for i in range(d):
    L[0][i]=1
for i in range(1,N):
    for j in range(K):
        L[i][j]=sum(L[i-1][max(j-d,0):j])
print(L[N-1][K-1]%(10**9+7))