#include <bits/stdc++.h>
using namespace std;
int main() {
  int x, y, n, a, b;
  long double mn = 1e9, target;
  scanf("%d%d%d", &x, &y, &n);
  target = x / (long double)y;
  ++n;
  for (int i = 1; i < n; ++i) {
    if (abs(target - floor(target * i) / i) < mn) {
      b = i;
      a = floor(target * i);
      mn = abs(target - floor(target * i) / i);
    }
    if (abs(target - ceil(target * i) / i) < mn) {
      b = i;
      a = ceil(target * i);
      mn = abs(target - ceil(target * i) / i);
    }
  }
  printf("%d/%d", a, b);
  return 0;
}
