#include <bits/stdc++.h>
int x, y, n, b;
long long a;
double m, t;
int main() {
  int i;
  long long j;
  std::scanf("%d%d%d", &x, &y, &n);
  m = 1;
  for (i = 1; i <= n; ++i) {
    j = (long long)i * x / y;
    t = (double)x / y - (double)j / i;
    if (t - m < -1e-15) m = t, b = i, a = j;
    ++j;
    t = (double)j / i - (double)x / y;
    if (t - m < -1e-15) m = t, b = i, a = j;
  }
  std::printf("%lld/%d\n", a, b);
  return 0;
}
