#include <bits/stdc++.h>
int n, a, b;
double x, y;
int main() {
  scanf("%lf%lf%d", &x, &y, &n);
  double x0 = x;
  double ans = 1000000000.0;
  int a, b0;
  for (int b = n; b >= 1; --b) {
    int sa;
    double oo;
    sa = x * b / y;
    if (fabs(x / y - (sa + 1) * 1.0 / b) <= ans)
      a = sa + 1, ans = fabs(x / y - (sa + 1) * 1.0 / b), b0 = b;
    if (fabs(x / y - sa * 1.0 / b) <= ans)
      a = sa, ans = fabs(x / y - sa * 1.0 / b), b0 = b;
    if (sa > 0 && fabs(x / y - (sa - 1) * 1.0 / b) <= ans)
      a = sa - 1, ans = fabs(x / y - (sa - 1) * 1.0 / b), b0 = b;
  }
  printf("%d/%d\n", a, b0);
  return 0;
}
