#include <bits/stdc++.h>
using namespace std;
int main() {
  long long x, y, n, minA, minB;
  scanf("%I64d%I64d%I64d", &x, &y, &n);
  double orig = (double)x / y, mini = orig * 2.0;
  for (long long b = 1; b <= n; b++) {
    long long a = x * b / y;
    if (fabs(((double)a / b) - orig) + 1e-15 < mini) {
      mini = fabs(((double)a / b) - orig);
      minA = a;
      minB = b;
    }
    a++;
    if (fabs(((double)a / b) - orig) + 1e-15 < mini) {
      mini = fabs(((double)a / b) - orig);
      minA = a;
      minB = b;
    }
  }
  printf("%I64d/%I64d\n", minA, minB);
  return 0;
}
