90分 WA最后一个点 帮帮蒻蒟吧（

#include <cstdio>
#include <algorithm>
#include <cmath>
using namespace std;
double a, b;
int n;

int main() {
   scanf("%lf%lf%d", &a, &b, &n);

   double k = a / b;
   for (int i = 1; i <= n; i++) {
   	int w = floor(k);
   	k -= w;
   	k *= 10;
   }
   int w = floor(k);

   printf("%d", w);
   return 0;
}