#include<iostream>
#include<string>
#include<algorithm>
#include<map>
#include<vector>
#include<cmath>
#include<cstdio>
#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)
#define pb(in,tmp) in.push_back(tmp)
#define all(in) in.begin(),in.end()
#define PI acos(-1)
using namespace std;
int main(){
  int a,b,n;
  while(cin>>a>>b>>n){
    int sum=0;
    rep(i,n){
      sum+=(int)((double)a/b*pow(10,i+1))-((int)((double)a/b*pow(10,i)))*10;
    }
    cout<<sum<<endl;
  }

}