#include<stdio.h>
int main()
{
int n;
scanf("%d", &n);
while(n--)
{
int a, b;
scanf("%d %d", &a, &b);
int i, t=0, j;
while(a/b)
{
t=t+a/b;
a=a/b;
}
printf("%d\n", t);
}
}
int main()
{
int n;
scanf("%d", &n);
while(n--)
{
int a, b;
scanf("%d %d", &a, &b);
int i, t=0, j;
while(a/b)
{
t=t+a/b;
a=a/b;
}
printf("%d\n", t);
}
}