#include <bits/stdc++.h>
const double EPS = 1e-9;
const int MOD = 1000003;
const int INF = 2000 * 1000 * 1000;
using namespace std;
int popcount(int n) {
  bitset<32> b(n);
  return b.count();
}
long long gcd(long long a, long long b) { return b == 0 ? a : gcd(b, a % b); }
int lcm(int a, int b) {
  int temp = gcd(a, b);
  return temp ? (a / temp * b) : 0;
}
template <typename T>
T modpow(T base, T exp, T modulus) {
  base %= modulus;
  T result = 1;
  while (exp > 0) {
    if (exp & 1) result = (result * base) % modulus;
    base = (base * base) % modulus;
    exp >>= 1;
  }
  return result;
}
inline bool isInteger(const std::string& s) {
  if (s.empty() || ((!isdigit(s[0])) && (s[0] != '-') && (s[0] != '+')))
    return false;
  char* p;
  strtol(s.c_str(), &p, 10);
  return (*p == 0);
}
int main() {
  long long a, b, n;
  cin >> a >> b >> n;
  long long bestden = 1, bestnum = 0;
  for (long long den = 1; den <= n; den++) {
    long long lower_estimate = a * den / b;
    long long upper_estimate = lower_estimate + 1;
    long long estimate = lower_estimate;
    if (abs(den * a - lower_estimate * b) > abs(den * a - upper_estimate * b))
      estimate = upper_estimate;
    if (abs(estimate * b - den * a) * bestden <
        abs(bestnum * b - bestden * a) * den) {
      bestnum = estimate;
      bestden = den;
    }
  }
  cout << bestnum << "/" << bestden << endl;
  return 0;
}
