#include<iostream>
using namespace std;

int main(){

  int ans,a,b,n;
  double k;

  while(cin >> a >> b >> n){
    k = (double)a / (double)b;
    ans = 0;

    for(int i=0;i<n;i++){
      k *= 10;

      ans += (int)k%10;
    }
    cout << ans << endl;
  }
}