Assume that a, b, and n are all positive integers. Let f (i) be the i-th fraction of the fraction a / b (0 ≤ f (i) ≤ 9). At this time, let s be the sum of f (i) from i = 1 to n.

s = f (1) + f (2) + ... + f (n)


Create a program that reads a, b, n, outputs s, and exits.



Input

The input consists of multiple datasets. For each dataset, three integers a (1 ≤ a ≤ 1000), b (1 ≤ b ≤ 10000), n (1 ≤ n ≤ 100) are given on one line, separated by blanks.

The number of datasets does not exceed 100.

Output

Prints s on one line for each dataset.

Example

Input

1 2 3
2 3 4
5 4 3
4 3 2


Output

5
24
7
6
#include <bits/stdc++.h>
using namespace std;
int main() {
  int c = 0;
  double a, b, sum = 0.0;
  double x[21] = {}, y[21] = {};
  while (scanf("%lf,%lf", &a, &b) != EOF) {
    if (c == 0) {
      x[c] = a;
      y[c] = b;
    } else {
      x[c] = a - x[0];
      y[c] = b - y[0];
    }
    c++;
  }
  for (int i = 1; i < c - 1; i++) {
    sum += 0.5 * abs(x[i] * y[i + 1] - x[i + 1] * y[i]);
  }
  printf("%.10lf\n", sum);
}
