# https://yukicoder.me/problems/no/269

MOD = 10 ** 9 + 7

def main():
    N, S, K = map(int, input().split())

    dp = [0] * (S + 1)
    x = 0
    while x <= S:
        dp[x] = 1
        x += N

    for i in range(1, N):
        n = N - i
        new_dp = [0] * (S + 1)

        for x in range(S + 1):
            y = K
            while x + n * y <= S:
                new_dp[x + n * y] += dp[x]
                new_dp[x + n * y] %= MOD
                y += 1
        
        dp = new_dp
    
    print(dp[S])
    





if __name__ == "__main__":
    main()