#include <bits/stdc++.h>
long long f(long long x) {
  if (x < 0) return -x;
  return x;
}
int main() {
  int x, y, n, p = -1, q, i;
  scanf("%d %d %d", &x, &y, &n);
  for (i = 1; i <= n; i++) {
    int z = (long long)x * i / y;
    if (p == -1 || f((long long)q * x - (long long)p * y) * i * y >
                       f((long long)i * x - (long long)z * y) * q * y) {
      p = z;
      q = i;
    }
    z++;
    if (f((long long)q * x - (long long)p * y) * i * y >
        f((long long)i * x - (long long)z * y) * q * y) {
      p = z;
      q = i;
    }
  }
  printf("%d/%d\n", p, q);
  return 0;
}
