#include <iostream>
#include <vector>
#include <algorithm>
#include <cassert>
#warning That's the baby, that's not my baby

typedef long long ll;


/**

b[0] = a[1] = a[t + 1] = a[2 * t + 1] = ...
b[1] = a[2] = a[t + 2] = a[2 * t + 2] = ...
b[2] = a[3] = a[t + 3] = a[2 * t + 3] = ...

b[0] * x + b[1] * x + ... + b[i] * x + b[i + 1] * (x - 1) + b[i + 2] * (x - 1) + ...  b[t - 1] * (x - 1) = s

x * (b[0] + b[1] + ... + b[i]) + (x - 1) * (b[i + 1] + b[i + 2] + ... + b[t - 1]) = s

i = k % t, x = k / t + 1

x * a + b * (x - 1) = s

**/

const int mod = 1e9 + 7;
const int NMAX = 1e7;

int fac[NMAX + 1], ifac[NMAX + 1];

int power(int a, int b) {
  int p = 1;
  while (b) {
    if (b & 1) {
      p = (ll) p * a % mod;
    }
    a = (ll) a * a % mod;
    b >>= 1;
  }
  return p;
}

int C(int n, int k) {
  if (n < k) {
    return 0;
  }
  return (ll) fac[n] * ifac[k] % mod * ifac[n - k] % mod;
}

int sb(int n, int k) {
  return C(k - 1, n - 1);
}

int main() {
  fac[0] = 1;
  for (int i = 1; i <= NMAX; i++) {
    fac[i] = (ll) fac[i - 1] * i % mod;
  }
  ifac[NMAX] = power(fac[NMAX], mod - 2);
  for (int i = NMAX - 1; i >= 0; i--) {
    ifac[i] = (ll) ifac[i + 1] * (i + 1) % mod;
  }
  for (int i = 0; i <= NMAX; i++) {
    assert((ll) fac[i] * ifac[i] % mod == 1);
  }

  int k, s, t;
  std::cin >> k >> s >> t;

  int i = k % t, x = k / t + 1; // x >= 2

  if (i == 0) {
    if (s % (x - 1) != 0) {
      std::cout << 0;
    } else {
      std::cout << sb(t, s / (x - 1));
    }
    return 0;
  }

  /// x * a + b * (x - 1) = s

  int answer = 0;

  for (int a = 0; a * x <= s; a++) {
    int b = s - a * x;
    if (b % (x - 1) != 0) {
      continue;
    }
    b /= x - 1;
    /// a = suma primelor i, b = suma ultimelor t - i
    answer += (ll) sb(i, a) * sb(t - i, b) % mod;

    if (answer >= mod) {
      answer -= mod;
    }
  }

  std::cout << answer;

  return 0;
}