#include <bits/stdc++.h>
#include <cassert>
#define rep(i, n) for (int i = 0; i < (n); i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;
struct Edge
{
  int to;
  int weight;
  Edge(int t, int w) : to(t), weight(w) {}
};
using Graph = vector<vector<Edge>>;
// using Graph = vector<vector<int>>;

const long long INF = 1LL << 60;
const int INT_INF = 1000000000;

int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
// int dx[8] = {-1, -1, -1, 0, 0, 1, 1, 1}, dy[8] = {-1, 0, 1, 1, -1, 1, 0, -1};
const int MOD = 1000000007;
const int MAX_N = 21000;
const int MAX_K = 110;
int PartNum[MAX_N + 1][MAX_K + 1];

void initPartNum()
{
  for (int n = 0; n <= MAX_N; ++n)
    for (int k = 0; k <= MAX_K; ++k)
      PartNum[n][k] = -1;
}

int calcPartNum(int n, int k)
{
  if (n == 0 && k == 0)
    return 1;
  if (n < 0 || k <= 0)
    return 0;
  if (PartNum[n][k] != -1)
    return PartNum[n][k];
  PartNum[n][k] = 0;
  PartNum[n][k] += calcPartNum(n, k - 1);
  PartNum[n][k] += calcPartNum(n - k, k);
  if (PartNum[n][k] >= MOD)
    PartNum[n][k] -= MOD;
  return PartNum[n][k];
}

int main()
{
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int N, S, K;
  cin >> N >> S >> K;
  initPartNum();
  int n = S - N * (N - 1) / 2 * K;
  int k = N;
  cout << calcPartNum(n, k) << endl;
  return 0;
}