import sys

sys.setrecursionlimit(10 ** 6)
def MI(): return map(int, sys.stdin.readline().split())

md = 10 ** 9 + 7
def main():
    # n人でx円払う方法
    memo = {}
    def p(n, x):
        if n == 1: return 1
        if (n, x) in memo: return memo[n, x]
        res = 0
        for a in range(x // n + 1):
            res += p(n - 1, x - a * n)
        res %= md
        memo[n, x] = res
        return res

    n, s, k = MI()
    print(p(n, s - k * n * (n - 1) // 2))

main()