#include <iostream>
#include <cstdio>
#include<list>
#include<iomanip>
#include<cmath>
#include <random>
#include<queue>
#include <functional>
#include<stdio.h>
#include<assert.h>
#include<stack>
#include<sstream>
#include <cstdlib>
#include<map>
#include<algorithm>
#include<iostream>
#include<set>
#include<utility>
#include<memory.h>
#include<string>
#include<vector>
#include <unordered_map>
#include<numeric>
using namespace std;
#define ios std::ios_base::sync_with_stdio(false);
#define ll  long long
#define pb push_back
#define fi(ss) freopen (ss,"r",stdin)
#define fo(ss) freopen (ss,"w",stdout)
#define sz(v)               ((int)((v).size()))
#define all(x)          (x).begin(),(x).end()
#define REP(i, v)       for(int i=0;i<sz(v);i++)
#define lp(i,n) for(int i = 0 ; i < n ; ++i)
typedef pair<ll,ll> pii;
typedef pair<pii,int> tri;
const int maxn = 2 * 100005;
using namespace std;
using namespace std;
int n,s,k;
 int mod = 1000*1000*1000 + 7;
 int dp[101][20005];
int solve(int ind,int s) {
	if (s < 0) {
		return 0;
	}
	if (ind == n) {
		return  s == 0 ? 1 : 0;
	}
	if (dp[ind][s] != -1) {
		return dp[ind][s];
	}
	int ret = 0;
	ret += solve(ind + 1,s);
	ret %= mod;
	ret += solve(ind,s - (n - ind));
	ret %= mod;
	return dp[ind][s] = ret;
};
int main() {
	cin >> n >> s >> k;
	memset(dp,-1,sizeof(dp));

	for (int i = 0 ; i < n ; ++i) {
			s -= i * k;
		}
		cout << solve(0,s) << "\n";


}