#include <iostream>
using namespace std;
const int N = 3010, M = 1510, mod = 1e9 + 7;
int f[N][M];
int t, d, m;
int main()
{
cin >> d >> t >> m;
f[0][m] = 1;
for(int i = 1; i <= t; i++)
{
for(int j = 0; j <= m; j++)
{
if(d + (m - j) - (i - (m - j)) > 0)
f[i][j] = (f[i - 1][j] + f[i - 1][j + 1]) % mod;
}
}
cout << f[t][0];
return 0;
}