#define _USE_MATH_DEFINES
#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define MT make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
#define RT return
#define vv(a,b,c,d) vector<vector<a> >(b,vector<a>(c,d))
#define vvv(a,b,c,d,e) vector<vector<vector<a> > >(b,vv(a,c,d,e))
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(20);
    int N, S, K, M = (int)1e9+7;
    cin >> N >> S >> K;
    vi cu(S + 1), ne(S + 1);
    int p = 0;
    while (p*N <= S)cu[p++*N] = 1;
    FOR(i, 1, N) {
        fill(all(ne), 0);
        rep(j, S + 1) {
            FOR(k, K, S + 1) {
                int l = j + k * (N - i);
                if (l > S)break;
                ne[l] += cu[j];
                if (ne[l] >= M)ne[l] -= M;
            }
        }
        swap(cu, ne);
    }
    cout << cu[S] << endl;
}