#include <iostream>
#include <complex>
#include <sstream>
#include <string>
#include <algorithm>
#include <deque>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <vector>
#include <set>
#include <limits>
#include <cstdio>
#include <cctype>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <ctime>
using namespace std;
#define REP(i, j) for(int i = 0; i < (int)(j); ++i)
#define FOR(i, j, k) for(int i = (int)(j); i < (int)(k); ++i)
#define SORT(v) sort((v).begin(), (v).end())
#define REVERSE(v) reverse((v).begin(), (v).end())
typedef complex<double> P;

int solve(int A, int B, int N){
  int res = 0;
  double tmp = (double)(A) / B;
  tmp *= 10;
  REP(i, N){
    res += (int)(tmp) % 10;
    tmp *= 10;
  }
  return res;
}

int main() {
  int A, B, N;
  while(cin >>A){
    cin >>B >>N;
    cout <<solve(A, B, N) <<endl;
  }
  return 0;
}