// 基本テンプレート (縮小版)

#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,n) for(int (i)=(a); (i)<(n); (i)++)
#define repq(i,a,n) for(int (i)=(a); (i)<=(n); (i)++)
#define repr(i,a,n) for(int (i)=(a); (i)>=(n); (i)--)
#define int long long
template<typename T> void chmax(T &a, T b) {a = max(a, b);}
template<typename T> void chmin(T &a, T b) {a = min(a, b);}
template<typename T> void chadd(T &a, T b) {a = a + b;}
typedef pair<int, int> pii;
typedef long long ll;
constexpr ll INF = 1001001001001001LL;
constexpr ll MOD = 1000000007LL;

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

signed main() {
    dp[1][0] = 1;
    cin >> N >> S >> K;
    rep(i,0,N) repq(j,0,S) {
        if((N-i) * K <= j) (dp[i+1][j] += dp[i][j-(N-i)*K]) %= MOD;
        if(N-i <= j) (dp[i+1][j] += dp[i+1][j-(N-i)]) %= MOD;
        // if(dp[i+1][j] != 0) printf("debug: dp[%lld][%lld] = %lld\n", i+1, j, dp[i+1][j]);
    }
    cout << dp[N][S] << endl;
    return 0;
}