#include <bits/stdc++.h>
using namespace std;
long long a, b1, n;
long long x, y;
float T(float a) {
  if (a < 0) a = a * (-1);
  return a;
}
int MIN(float a, float b, float c) {
  if (a <= b && a <= c) return 1;
  if (b <= a && b <= c) return 2;
  if (c <= b && c <= a) return 3;
}
int main() {
  cin >> x >> y >> n;
  double Min = 100000;
  for (int b = 1; b <= n; b++) {
    long long a1 = (x * b) / y;
    long long a0 = a1 - 1;
    long long a2 = a1 + 1;
    double t0 = T(x * 1.0 / y - a0 * 1.0 / b);
    double t1 = T(x * 1.0 / y - a1 * 1.0 / b);
    double t2 = T(x * 1.0 / y - a2 * 1.0 / b);
    int c = MIN(t0, t1, t2);
    if (c == 1 && t0 < Min) {
      a = a0;
      b1 = b;
      Min = t0;
    }
    if (c == 2 && t1 < Min) {
      a = a1;
      b1 = b;
      Min = t1;
    }
    if (c == 3 && t2 < Min) {
      a = a2;
      b1 = b;
      Min = t2;
    }
  }
  cout << a << "/" << b1;
}
