#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000000007;
int dp[70][50][50][50];
int tmp[50][50];
int base[50];
int get_dig(int pos, int k) {
  return (pos < k) ? pos : (get_dig(pos / k, k) + pos % k) % k;
}
inline int get_val(int depth, int i, int j, int shift, int k) {
  if (i == k && j < k) {
    return dp[depth][0][k][(j + k - shift) % k];
  } else if (i < k && j < k) {
    return dp[depth][0][(i + k - shift) % k][(j + k - shift) % k];
  }
  return dp[depth][0][i][j];
}
int main() {
  long long n;
  int k;
  cin >> n >> k;
  int max_depth = 0;
  {
    long long tmp = n;
    while (tmp != 0) {
      ++max_depth;
      tmp /= k;
    }
  }
  {
    for (int df = 0; df < 1; ++df) {
      for (int i = 0; i <= k; ++i) {
        for (int j = 0; j <= k; ++j) {
          dp[0][df][i][j] = (i == j || j == df);
        }
      }
    }
    for (int depth = 1; depth < max_depth; ++depth) {
      for (int df = 0; df < 1; ++df) {
        for (int i = 0; i <= k; ++i) {
          for (int j = 0; j <= k; ++j) {
            dp[depth][df][i][j] = (i == j);
          }
        }
        for (int pos = 0; pos < k; ++pos) {
          for (int i = 0; i <= k; ++i) {
            for (int j = 0; j <= k; ++j) {
              tmp[i][j] = 0;
              for (int l = 0; l <= k; ++l) {
                tmp[i][j] = (tmp[i][j] +
                             1ll * dp[depth][df][i][l] *
                                 get_val(depth - 1, l, j, (pos + df) % k, k)) %
                            MOD;
              }
            }
          }
          for (int i = 0; i <= k; ++i) {
            for (int j = 0; j <= k; ++j) {
              dp[depth][df][i][j] = tmp[i][j];
            }
          }
        }
      }
    }
  }
  for (int i = 0; i <= k; ++i) {
    base[i] = (i == k);
  }
  int sl = 0;
  long long x = n;
  vector<int> vec;
  while (x != 0) {
    vec.push_back(x % k);
    x /= k;
  }
  int len = int(vec.size());
  for (int cur_depth = len - 1; cur_depth >= 0; --cur_depth) {
    int rest = vec[cur_depth];
    for (int it = 0; it < rest; ++it, sl = (sl + 1) % k) {
      for (int i = 0; i <= k; ++i) {
        tmp[0][i] = 0;
        for (int l = 0; l <= k; ++l) {
          tmp[0][i] =
              (tmp[0][i] + 1ll * base[l] * get_val(cur_depth, l, i, sl, k)) %
              MOD;
        }
      }
      for (int i = 0; i <= k; ++i) {
        base[i] = tmp[0][i];
      }
    }
  }
  {
    int res = 0;
    for (int i = 0; i <= k; ++i) {
      res = (res + base[i]) % MOD;
    }
    cout << res << '\n';
  }
  return 0;
}
