#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<cmath>
using namespace std;
#define loop(i,a,b) for(int i = a ; i < b; i ++)
#define rep(i,a) for(int i = 0 ; i < a; i ++)
int main(void){
  int a,b,n;
  while(cin>>a>>b>>n){

    int res = 0;
    loop(i,1,n+1){
      //cout<<pow(10,i)<<endl;
      res += (int)(a*1.0/b *pow(10,i) )%10;
      //cout<<(int)(a*1.0/b *pow(10,i) )%10<<endl;
    }
    
    /*
    rep(i,n)po *= 10;
    po = now * po;
    rep(i,n){
      res += po%10;
      po /= 10;
    }
    */

    /*
    rep(i,n){
   
      res += (int)(now*10)%10/1;
      now *= 10;
    }
    //*/
    cout<<res<<endl;
  }
}