# 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)

        cum_dp = [0] * (n + 1)
        for x0 in range(S + 1):
            y = x0 // n
            if y >= K:
                cum_dp[x0 % n] += dp[(x0 % n) + ((y - K) * n)]
                cum_dp[x0 % n] %= MOD        

            new_dp[x0] += cum_dp[x0 % n]
            new_dp[x0] %= MOD
            
        dp = new_dp
    
    print(dp[S])
    





if __name__ == "__main__":
    main()