import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################
n,s,k = na()
dp = [0] * (s+1)
dp[0] = 1
mod = 10**9+7
ndp = [0] * (s+1)
dp,ndp = ndp,dp
i = 0
for j in range(s+1):
    if ndp[j] == 0:
        continue
    for x in range(0, s+1):
        nj = j + x * (n - i)
        if nj > s:
            break
        dp[nj] += ndp[j]
        dp[nj] %= mod
for i in range(1,n):
    ndp = [0] * (s+1)
    dp,ndp = ndp,dp
    for j in range(s+1):
        if ndp[j] == 0:
            continue
        for x in range(k, s+1):
            nj = j + x * (n - i)
            if nj > s:
                break
            dp[nj] += ndp[j]
            dp[nj] %= mod
print(dp[-1])