import java.util.*;

public class Main {
    static final int MOD = 1000000007;
	public static void main (String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int s = sc.nextInt();
		int kk = sc.nextInt();
		int min = n * (n - 1) * kk / 2;
		if (s < min) {
		    System.out.println(0);
		    return;
		}
		s -= min;
		HashMap<Integer, Integer> map = new HashMap<>();
		for (int i = 0; i * n <= s; i++) {
		    map.put(i * n, 1);
		}
		for (int i = 2; i <= n; i++) {
		    HashMap<Integer, Integer> next = new HashMap<>();
		    for (Map.Entry<Integer, Integer> entry : map.entrySet()) {
		        int key = entry.getKey();
		        int value = entry.getValue();
		        for (int j = 0; key + j * (n - i + 1) <= s; j++) {
		            int nkey = key + j * (n - i + 1);
		            if (next.containsKey(nkey)) {
		                next.put(nkey, (next.get(nkey) + value) % MOD);
		            } else {
		                next.put(nkey, value);
		            }
		        }
		    }
		    map = next;
		}
		System.out.println(map.get(s));
	}
}