#include<stdio.h>
#include<iostream>
#include<list>
#include<map>
#include<vector>
#include<algorithm>
#include<string.h>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) range(i,0,b)
#define debug(x) cout << x << endl;
using namespace std;

int main(){
    double a,b,n;
    double large;
    int sum;
    while(cin >> a >> b >> n){
        sum = 0;
        large = a / b;
        rep(i,n){
            while(large >= 1)
                large--;
            large *= 10;
            sum += large;
        }
        cout << sum << endl;
    }
}