#include <bits/stdc++.h>

using namespace std;

using int64 = long long;
const int mod = 1e9 + 7;


int N, S, K;
int dp[101][20001];

int rec(int idx, int rest) {
  if(idx == 0) return rest == 0;
  if(~dp[idx][rest]) return dp[idx][rest];
  int ret = 0;
  for(int v = K; v * idx <= rest; v++) {
    (ret += rec(idx - 1, rest - v * idx)) %= mod;
  }
  return dp[idx][rest] = ret;
}

int main() {
  cin >> N >> S >> K;
  memset(dp, -1, sizeof(dp));
  int ret = 0;
  for(int i = 0; i * N <= S; i++) {
    (ret += rec(N - 1, S - i * N)) %= mod;
  }
  cout << ret << endl;
}