#include <bits/stdc++.h>
int main() {
  double x, y;
  int n;
  double min, m, zi, mu, mins, a, b;
  while (scanf("%lf%lf%d", &x, &y, &n) != EOF) {
    min = 999;
    m = x / y;
    while (n >= 1) {
      b = n;
      a = int(x * b / y + 1);
      mins = fabs(m - a / b);
      if (min >= mins) {
        min = mins;
        zi = a;
        mu = b;
      }
      a--;
      mins = fabs(m - a / b);
      if (mins <= min) {
        zi = a;
        mu = b;
        min = mins;
      }
      n--;
    }
    printf("%.0f/%.0f\n", zi, mu);
  }
  return 0;
}
