//compiler options: /t:library
using System;

class Frac {
  int a, b; // razlomak je oblika a/b gde je b > 0

  public int Num() { return a; }
  
  public int Den() { return b; }

  public Frac(int n) {
    a = n; b = 1;
  }

    public Frac(int p, int q) {
    if(q == 0) { throw new Exception("Imenilac razlomka je 0"); }
    if(q < 0) { p = -p; q = -q; }
    int d = GCD(Math.Abs(p), q);
    a = p / d; b = q / d;
  }
  
  static int GCD(int a, int b) {
    // znamo da je a >= 0 i b >= 0
    if(a == 0) { return b; }
    if(b == 0) { return a; }
    int r;
    do {
      r = a % b; a = b; b = r;
    } while(r > 0);
    return a;
  }

  public static Frac Parse(string s) {
    string t = "";
    foreach(char c in s) {
      if(!Char.IsWhiteSpace(c)) { t += c; }
    }
    if(String.IsNullOrEmpty(t)) {
      throw new Exception("Nije dobar zapis razlomka");
    }
    int k = t.IndexOf('/');
    if(k == -1) { return new Frac(int.Parse(t)); }
    return new Frac(int.Parse(t.Substring(0, k)),
                    int.Parse(t.Substring(k+1)));
  }

  public override string ToString() {
    if(a == 0) { return "0"; }
    if(b == 1) { return a.ToString(); }
    return a.ToString() + "/" + b.ToString();
  }

  public Frac Copy() { return new Frac(a, b); }

  public bool Equals(Frac r) {
    return a == r.a && b == r.b;
  }

  public int Compare(Frac r) {
    if(Equals(r)) { return 0; }
    if(a * r.b < r.a * b) { return -1; }
    return 1;
  }

  public static Frac operator + (Frac r, Frac s) {
    return new Frac(r.Num()*s.Den() + s.Num()*r.Den(), r.Den()*s.Den());
  }

  public static Frac operator + (Frac r, int s) {
    return r + new Frac(s);
  }

  public static Frac operator + (int r, Frac s) {
    return new Frac(r) + s;
  }

  public static Frac operator - (Frac r, Frac s) {
    return new Frac(r.Num()*s.Den() - s.Num()*r.Den(), r.Den()*s.Den());
  }

  public static Frac operator - (Frac r, int s) {
    return r - new Frac(s);
  }

  public static Frac operator - (int r, Frac s) {
    return new Frac(r) - s;
  }

  public static Frac operator - (Frac r) {
    return new Frac(-r.Num(), r.Den());
  }

  public static Frac operator * (Frac r, Frac s) {
    return new Frac(r.Num()*s.Num(), r.Den()*s.Den());
  }

  public static Frac operator * (Frac r, int s) {
    return r * new Frac(s);
  }

  public static Frac operator * (int r, Frac s) {
    return new Frac(r) * s;
  }
  
  public static Frac operator / (Frac r, Frac s) {
    return new Frac(r.Num()*s.Den(), r.Den()*s.Num());
  }

  public static Frac operator / (Frac r, int s) {
    return r / new Frac(s);
  }

  public static Frac operator / (int r, Frac s) {
    return new Frac(r) / s;
  }

  public static implicit operator Frac(int n) {
     return new Frac(n);
  }
}