#include <iostream>
using namespace std;

int main(void) {
  int a, b, n;

  while (cin >> a >> b >> n) {
    int ans = 0;
    
    for (int i = 0; i < n; i++) {
      a = 10 * (a % b);
      ans += a / b;
    }

    cout << ans << endl;
  }

  return 0;
}