#include <bits/stdc++.h>
using namespace std;
struct ww {
  int a[40][40];
} a[40], b[40], c, d[40];
int i, j, k, K, m;
long long n;
inline ww multi(ww a, ww b) {
  ww c = {};
  int i, j, k;
  for (i = 0; i <= K; i++)
    for (j = 0; j <= K; j++)
      for (k = 0; k <= K; k++)
        c.a[i][j] = (1ll * a.a[i][k] * b.a[k][j] + c.a[i][j]) % 1000000007;
  return c;
}
inline void merge() {
  int i;
  b[0] = a[0];
  for (i = 1; i <= K - 1; i++) b[i] = multi(b[i - 1], a[i]);
  d[K - 1] = a[K - 1];
  for (i = K - 2; i >= 0; i--) d[i] = multi(a[i], d[i + 1]);
  for (i = 0; i <= K - 1; i++)
    if (i == 0)
      a[i] = d[0];
    else
      a[i] = multi(d[i], b[i - 1]);
}
int main() {
  scanf("%I64d%d", &n, &K);
  for (i = 0; i <= K - 1; i++) {
    for (j = 0; j <= K - 1; j++)
      if (i != j) {
        a[i].a[j][j] = 1;
      } else {
        for (k = 0; k <= K; k++) a[i].a[k][j] = 1;
      }
    a[i].a[K][K] = 1;
  }
  for (i = 0; i <= K; i++) c.a[i][i] = 1;
  for (; n; n /= K) {
    int A = n % K;
    if (A) {
      int s = 0;
      long long v;
      for (v = n; v; v /= K) s = (v / K + s) % K;
      int End = (s + A - 1) % K;
      for (;;) {
        c = multi(a[End], c);
        if (End == s) break;
        End--;
        if (End < 0) End += K;
      }
    }
    merge();
  }
  int an = 1;
  for (i = 0; i <= K - 1; i++) an = (an + c.a[K][i]) % 1000000007;
  printf("%d\n", an);
  return 0;
}
