using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;

class Program
{
    public void Proc()
    {
        Reader.IsDebug = false;
        int[] inpt = Reader.GetInt();
        this.seitoCount = inpt[0];
        this.goalValue = inpt[1];
        this.addVal = inpt[2];
        this.Init();
        if(goalValue < 0) {
            Console.WriteLine(0);
            return;
        }
        this.dic = new long[seitoCount, goalValue + 1];
        long ans = this.GetAns(0, this.goalValue);
        Console.WriteLine(ans);
    }
    
    private long ModNum = 1000000000 + 7;
    
    private long GetAns(int idx, int remain) {
        if(this.dic[idx, remain] > 0) {
            return this.dic[idx, remain];
        }
        long ans = 0;
        if(remain == 0) {
            ans = 1;
        } else if(idx == this.seitoCount - 1) {
            ans = 1;
        } else
        {
            for(int i=0; i * (this.seitoCount - idx) <=remain; i++) {
                ans += this.GetAns(idx+1, remain - i * (this.seitoCount - idx));
                ans = ans % this.ModNum;
            }
        }
        this.dic[idx, remain] = ans;
        return ans;
    }
    
    
    private long[,] dic;
    
    private void Init() {
        int minus = 0;
        for(int i=seitoCount - 1; i>=1; i--) {
            minus += i * addVal;
        }
        this.goalValue -= minus;
    }
    
    private int seitoCount = 0;
    private int goalValue = 0;
    private int addVal = 0;
    


    public class Reader
    {
        public static bool IsDebug = true;
        private static String PlainInput = @"


55 2555 1


 
";
        private static System.IO.StringReader Sr = null;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (Sr == null)
                {
                    Sr = new System.IO.StringReader(PlainInput.Trim());
                }
                return Sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
        public static int[] GetInt(char delimiter = ' ', bool trim = false)
        {
            string inptStr = ReadLine();
            if (trim)
            {
                inptStr = inptStr.Trim();
            }
            string[] inpt = inptStr.Split(delimiter);
            int[] ret = new int[inpt.Length];
            for (int i = 0; i < inpt.Length; i++)
            {
                ret[i] = int.Parse(inpt[i]);
            }
            return ret;
        }
    }
    static void Main()
    {
        Program prg = new Program();
        prg.Proc();
    }
}