#include <bits/stdc++.h>
using namespace std;
long long x, y, n;
long long maxx = 0, maxy = 1;
long long a[1000100], b[1000100];
int cnt = 0;
double temp;
int main() {
  scanf("%d %I64d %I64d", &x, &y, &n);
  for (int i = 1; i <= n; i++) {
    temp = (double)i * x / y;
    a[cnt] = floor(temp);
    b[cnt] = i;
    cnt++;
    a[cnt] = a[cnt - 1] + 1;
    b[cnt] = i;
    cnt++;
  }
  for (int i = 0; i < cnt; i++) {
    long long hehe = abs(b[i] * y * (x * maxy - y * maxx));
    long long heihei = abs(y * maxy * (b[i] * x - a[i] * y));
    if (hehe > heihei) {
      maxx = a[i];
      maxy = b[i];
    }
  }
  printf("%I64d/%I64d\n", maxx, maxy);
  return 0;
}
