#include<bits/stdc++.h>
using namespace std;
#define inf INT_MAX
#define INF LLONG_MAX
#define ll long long
#define ull unsigned long long
#define M (int)(1e9+7)
#define P pair<int,int>
#define PLL pair<ll,ll>
#define FOR(i,m,n) for(int i=(int)m;i<(int)n;i++)
#define RFOR(i,m,n) for(int i=(int)m;i>=(int)n;i--)
#define rep(i,n) FOR(i,0,n)
#define rrep(i,n) RFOR(i,n,0)
#define all(a) a.begin(),a.end()
#define IN(a,n) rep(i,n){ cin>>a[i]; }
const int vx[4] = {0,1,0,-1};
const int vy[4] = {1,0,-1,0};
#define PI 3.14159265
#define F first
#define S second
#define PB push_back
#define EB emplace_back
#define int ll
#define vi vector<int>

int n,s,k;
int memo[110][21000];

int dfs(int t,int l,int j){

  if(j==n-1&&t>=l+k) return memo[j][t]=1;
  if(j==n-1) return memo[j][t]=0;
  if(memo[j][t]!=-1) return memo[j][t];

  int res=0;
  FOR(i,l+k,t){
    res+=dfs(t-i,i,j+1);
    res%=M;
  }

  return memo[j][t]=res;
}


signed main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  cin>>n>>s>>k;

  rep(i,n+1){
    rep(j,s+1){
      memo[i][j]=-1;
    }
  }

  int ans=0;

  rep(i,s+1){
    ans+=dfs(s-i,i,1);
    //cout<<ans<<endl;
    ans%=M;
  }


  cout<<ans<<endl;
}