#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
int add(int a, int b) {
  a += b;
  a += (a < 0) * mod - (a >= mod) * mod;
  return a;
}
int mul(int a, int b) { return 1LL * a * b % mod; }
struct mat {
  int n, m;
  vector<vector<int>> a;
  mat(int x = 0, int y = 0) {
    n = x, m = y;
    a.resize(n, vector<int>(m, 0));
  }
  void identity() {
    assert(n == m);
    for (int i = 0; i < n; i++)
      for (int j = 0; j < m; j++) a[i][j] = i == j;
  }
  void clear() {
    for (int i = 0; i < n; i++)
      for (int j = 0; j < m; j++) a[i][j] = 0;
  }
  void resize(int x, int y) {
    n = x, m = y;
    a.resize(n, vector<int>(m, 0));
  }
  mat operator*(const mat &b) {
    assert(m == b.n);
    mat res(n, b.m);
    for (int i = 0; i < n; i++)
      for (int j = 0; j < b.m; j++)
        for (int k = 0; k < m; k++)
          res.a[i][j] = add(res.a[i][j], mul(a[i][k], b.a[k][j]));
    return res;
  }
  void operator*=(const mat &b) { *this = *this * b; }
  mat operator^(long long b) {
    mat res(n, m), add = *this;
    for (res.identity(); b; b >>= 1, add *= add)
      if (b & 1) res *= add;
    return res;
  }
  void operator^=(long long b) { *this = *this ^ b; }
};
int main() {
  ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  long long n, k;
  cin >> n >> k;
  mat cnt(1, k + 1);
  cnt.a[0][k] = 1;
  mat A[60][k];
  for (int i = 0; i < k; i++) {
    A[0][i].resize(k + 1, k + 1);
    A[0][i].identity();
    for (int j = 0; j <= k; j++) A[0][i].a[j][i] = 1;
  }
  vector<int> vec;
  while (n) {
    vec.push_back(n % k);
    n /= k;
  }
  int x = 0, sz = (int)(vec.size());
  for (int i = 1; i < sz; i++) {
    mat pre[k];
    for (int i = 0; i < k; i++) pre[i].resize(k + 1, k + 1);
    pre[0] = A[i - 1][0];
    for (int j = 1; j < k; j++) pre[j] = pre[j - 1] * A[i - 1][j];
    mat suf[k];
    for (int i = 0; i < k; i++) suf[i].resize(k + 1, k + 1);
    suf[k - 1] = A[i - 1][k - 1];
    for (int j = k - 2; j >= 0; j--) suf[j] = A[i - 1][j] * suf[j + 1];
    for (int j = 0; j < k; j++) {
      A[i][j] = suf[j];
      if (j) A[i][j] *= pre[j - 1];
    }
  }
  for (int i = sz - 1; i >= 0; i--)
    for (int j = 0; j < vec[i]; j++) {
      cnt *= A[i][x];
      (x += 1) %= k;
    }
  int ans = 0;
  for (int i = 0; i <= k; i++) ans = add(ans, cnt.a[0][i]);
  cout << ans << '\n';
  return 0;
}
