#include <bits/stdc++.h>
using namespace std;
const int inf = (int)1e9;
int main() {
  int x, y, n;
  scanf("%d%d%d", &x, &y, &n);
  int a = 0, b = 1;
  for (int i = 1; i <= n; ++i) {
    long long delta = abs((long long)x * i * b - (long long)a * i * y);
    int t1 = (double)x * i / y;
    int t2 = t1 + 1;
    long long td1 = abs((long long)t1 * b * y - (long long)x * i * b);
    long long td2 = abs((long long)t2 * b * y - (long long)x * i * b);
    if (td1 < delta) delta = td1, a = t1, b = i;
    if (td2 < delta) delta = td2, a = t2, b = i;
  }
  printf("%d/%d\n", a, b);
  return 0;
}
