#include <iostream>
#include <cstdio>
#include <string>
#include <algorithm>
using namespace std;

#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define DEB 0

int main(){
  int a,b,n;
  while(~scanf("%d%d%d",&a,&b,&n)){
    int sum = 0;
    while(n){
      if( a/b==0 ){
	int k = a*10/b;
	sum += k;
	a = a*10 - k*b;
	n--;
      }else{
	int k = a/b;
	a = a - k*b;
      }
#if DEB
      printf("%d/%d\n",a,b);
#endif
    }
    printf("%d\n",sum);
  }
  return 0;
}