n, s, k = map(int, input().split())
mod = 10**9+7

dp = [0]*(s+1)
for i in range(0, s+1, n):
  dp[i] = 1
for i in range(1, n):
  t = [0]*i
  dp_ = [0]*(s+1)
  for j in range(s+1):
    if j-i*k>=0:
      t[j%i] += dp[j-i*k]
      t[j%i] %= mod
    dp_[j] = t[j%i]
  dp = dp_

print(dp[-1]%mod)