#include <bits/stdc++.h>
using namespace std;
int main() {
  int x, y, z, a, b;
  scanf("%d %d %d", &x, &y, &z);
  double ulm = (double)x / y;
  int za, zb;
  za = zb = 0;
  double zp = 10005;
  ;
  for (int i = 1; i <= z; ++i) {
    double k = ulm * i;
    int u = k;
    if (k - u > 0.5) u++;
    k = (double)u / i;
    k -= ulm;
    if (k < 0) k *= (-1);
    if (k < zp) {
      zp = k;
      za = u;
      zb = i;
    }
  }
  printf("%d/%d", za, zb);
}
