#include <bits/stdc++.h>
using namespace std;
long long x, y, n;
void read() { cin >> x >> y >> n; }
long long euclid(long long a, long long b) {
  if (a < b) swap(a, b);
  long long t;
  while (b) {
    t = b;
    b = a % t;
    a = t;
  }
  return a;
}
long long f(long long p, long long q) {
  long long nok = euclid(p, q);
  return p * q / nok;
}
const double eps = 0.00000000000001;
bool ask(double f1, double f2) {
  f1 *= 100000000000LL;
  f2 *= 100000000000LL;
  long long r1 = f1;
  long long r2 = f2;
  return r1 > r2;
}
bool fun(long long h1, long long h2, long long crdom, long long r1,
         long long r2) {
  long long d1 = f(crdom, r2);
  long long d2 = d1 / y;
  d2 *= x;
  long long t2 = d1 / h2;
  t2 *= h1;
  long long t3 = d1 / r2;
  t3 *= r1;
  return abs(d2 - t2) < abs(d2 - t3);
}
void solve() {
  long long dom, num, tmp, curdom, tmpn, tt, ansd, ansn;
  double diff = 10000000.0, cur, m;
  m = (double)x / y;
  for (int i = 1; i <= n; ++i) {
    dom = i;
    curdom = f(i, y);
    tmp = curdom / i;
    tmpn = curdom / y;
    tmpn *= x;
    tt = tmpn / tmp;
    cur = (double)tt / dom;
    cur -= m;
    cur = fabs(cur);
    if (diff == -2.0 || (fun(tt, dom, curdom, ansn, ansd))) {
      diff = cur;
      ansd = dom;
      ansn = tt;
    }
    tt++;
    cur = (double)tt / dom;
    cur -= m;
    cur = fabs(cur);
    if (diff == -2.0 || (fun(tt, dom, curdom, ansn, ansd))) {
      diff = cur;
      ansd = dom;
      ansn = tt;
    }
  }
  cout << ansn << '/' << ansd << endl;
}
int main() {
  read();
  solve();
  return 0;
}
