#include <stdio.h>
#include <stdint.h>
#include <inttypes.h>

int main() {
    int64_t n;
    int power;
    int sum = 0;

    scanf("%" SCNd64 "%d", &n, &power);

    while (n != 0) {
        sum += n % power;
        n /= power;
    }

    printf("%d\n", sum);
}