#include <bits/stdc++.h>
using namespace std;
template <typename C>
void ma(C& a, C b) {
  if (a < b) a = b;
}
template <typename C>
void mi(C& a, C b) {
  if (a > b) a = b;
}
const int P = 1e9 + 7;
int n;
long long pom[31][31];
struct m {
  long long t[31][31];
  void id() {
    for (int i = 0; i < n; i++)
      for (int j = 0; j < n; j++) t[i][j] = (i == j);
  }
  void operator*=(m& b) {
    for (int i = 0; i < n; i++)
      for (int j = 0; j < n; j++) pom[i][j] = 0;
    for (int i = 0; i < n; i++)
      for (int j = 0; j < n; j++)
        for (int k = 0; k < n; k++) pom[i][k] += t[i][j] * b.t[j][k] % P;
    for (int i = 0; i < n; i++)
      for (int j = 0; j < n; j++) t[i][j] = pom[i][j] % P;
  }
} obr, nl, ak, d[31 * 2];
long long m;
long long pw[31];
long long wyn[31];
int k;
vector<int> roz;
int main() {
  scanf("%lld%d", &m, &k);
  while (m) {
    roz.push_back(m % k);
    m /= k;
  }
  n = k + 1;
  for (int i = 0; i < k; i++) obr.t[i][(i + 1) % k] = 1;
  obr.t[k][k] = 1;
  for (int i = 0; i < k + 1; i++) {
    nl.t[0][i] = 1;
    nl.t[i][i] = 1;
  }
  d[0] = nl;
  d[0] *= obr;
  for (int i = 1; i < roz.size(); i++) {
    d[i].id();
    for (int _ = 0; _ < k; _++) d[i] *= d[i - 1];
    d[i] *= obr;
  }
  for (int i = 0; i < n; i++) wyn[i] = 1;
  for (int ii = roz.size() - 1; ii >= 0; ii--) {
    for (int _ = 0; _ < roz[ii]; _++) {
      for (int i = 0; i < n; i++) pw[i] = 0;
      for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++) pw[j] += wyn[i] * d[ii].t[i][j] % P;
      for (int i = 0; i < n; i++) wyn[i] = pw[i] % P;
    }
  }
  printf("%lld\n", wyn[k]);
}
