#include <iostream>

#include <cmath>

#include <cstring>

#include <iomanip>

using namespace std;

int gcd(int x,int y)

{

    x=abs(x);

    y=abs(y);

    if(x<y)

    {

        int t=x;

        x=y;

        y=t;

    }

    if(x%y==)

        return y;

    else

        return gcd(x%y,y);

}

class Rational

{

private:

    int z;    //分子

    int m;    //分母

public:

    Rational(int a=, int b=)//构造有理数分数，分子默认为0，分母默认为1

    {

        z=a;

        m=b;

    }

    friend Rational& yuefen(Rational& r)//约分函数对分数化简

    {

        int c;

        c=gcd(r.z,r.m);

        r.z=r.z/c;

        r.m=r.m/c;

        if(r.z>&&r.m<)

        {

            r.z=-r.z;

            r.m=-r.m;

        }

        if(r.z<&&r.m<)

        {

            r.z=abs(r.z);

            r.m=abs(r.m);

        }

        return r;

    }

    friend Rational operator+(const Rational &r1, const Rational &r2)

    {

        Rational t;

        t.m=r1.m*r2.m;

        t.z=r1.z*r2.m+r2.z*r1.m;

        return t;

    }

    friend Rational operator-(const Rational &r1, const Rational &r2)

    {

        Rational t;

        t.m=r1.m*r2.m;

        t.z=r1.z*r2.m-r2.z*r1.m;

        return t;

    }

    friend Rational operator*(const Rational &r1, const Rational &r2)

    {

        Rational t;

        t.m=r1.m*r2.m;

        t.z=r1.z*r2.z;

        return t;

    }

    friend Rational operator/(const Rational &r1, const Rational &r2)

    {

        Rational t;

        t.m=r1.m*r2.z;

        t.z=r1.z*r2.m;

        return t;

    }

    Rational & operator+=(const Rational &r)

    {

        Rational t;

        t.m=this->m*r.m;

        t.z=this->z*r.m+r.z*this->m;

        this->z=t.z;

        this->m=t.m;

        return *this;

    }

    Rational & operator-=(const Rational &r)

    {

        Rational t;

        t.m=this->m*r.m;

        t.z=this->z*r.m-r.z*this->m;

        this->m=t.m;

        this->z=t.z;

        return *this;

    }

    Rational & operator*=(const Rational &r)

    {

        this->m=this->m*r.m;

        this->z=this->z*r.z;

        return *this;

    }

    Rational & operator/=(const Rational &r)

    {

        Rational t;

        t.m=this->m*r.z;

        t.z=this->z*r.m;

        this->m=t.m;

        this->z=t.z;

        return *this;

    }

    friend bool operator==(const Rational &s1, const Rational &s2)//判断两个有理数是否相等

    {

        int m1,m2,z1,z2,t1,t2;

        t1=gcd(s1.z,s1.m);

        t2=gcd(s2.z,s2.m);

        m1=s1.m/t1;

        m2=s2.m/t2;

        z1=s1.z/t1;

        z2=s1.z/t2;

        if(m1==m2&&z1==z2)

            return ;

        else

            return ;

    }

    friend bool operator!=(const Rational &s1, const Rational &s2)//判断两个有理数是否不等

    {

        int m1,m2,z1,z2,t1,t2;

        t1=gcd(s1.z,s1.m);

        t2=gcd(s2.z,s2.m);

        m1=s1.m/t1;

        m2=s2.m/t2;

        z1=s1.z/t1;

        z2=s1.z/t2;

        if(m1==m2&&z1==z2)

            return ;

        else

            return ;

    }

    friend ostream & operator<<(ostream &t1, const Rational &t2)

    {

        t1<<t2.z<<"/"<<t2.m;

        return t1;

    }

    friend istream & operator>>(istream &t1, Rational &t2)

    {

        t1>>t2.z>>t2.m;

        return t1;

    }

};

int main()

{

    Rational r1,r2,r3;

    while(cin>>r1>>r2)

    {

        cout << "r1 = " << yuefen(r1) << "\n" << "r2 = " << yuefen(r2) << endl;

        r3 = r1 + r2;

        cout << "r1+r2 = " << yuefen(r3) << endl;

        r3 = r1 - r2;

        cout << "r1-r2 = " << yuefen(r3) << endl;

        r3 = r1 * r2;

        cout << "r1*r2 = " << yuefen(r3) << endl;

        r3 = r1 / r2;

        cout << "r1/r2 = " << yuefen(r3) << endl;

        cout << (r1 == r2) << " " << (r1 != r2) << endl;

        cout << yuefen(r1 += r2) << endl;

        cout << yuefen(r1 -= r2) << endl;

        cout << yuefen(r1 *= r2) << endl;

        cout << yuefen(r1 /= r2) << endl;

    }

    return ;

}

#include <iostream>

#include <cmath>

#include <cstring>

#include <iomanip>

using namespace std;

class CheckedPtr

{

public:

    CheckedPtr(int * b, int * e):beg(b), end(e), curr(b){  }

    CheckedPtr & operator ++()// prefix ++

    {

        this->curr+=;

        return *this;

    }

    CheckedPtr & operator --() // prefix --

    {

        this->curr-=;

        return *this;

    }

    CheckedPtr   operator ++(int)// postfix ++,()内int用于c区分前置后置

    {

        CheckedPtr t=*this;

        this->curr+=;

        return t;

    }

    CheckedPtr   operator --(int)// postfix --

    {

        CheckedPtr t=*this;

        this->curr-=;

        return t;

    }

    int * GetBeg()

    {

        return beg;

    }

    int * GetEnd()

    {

        return end;

    }

    int * GetCurr()

    {

        return curr;

    }

private:

    int * beg;  // pointer to beginning of the array

    int * end;  // one past the end of the array

    int * curr; // current position within the array

};

int main()

{

    int array[] = {,,,,,,,,,};

    CheckedPtr cp(array, array+);

    for(;cp.GetCurr()<cp.GetEnd();cp++)

        cout<<*cp.GetCurr()<<" ";

    cout<<endl;

    for(--cp;cp.GetCurr()>cp.GetBeg();cp--)

        cout<<*cp.GetCurr()<<" ";

    cout<<*cp.GetCurr()<<endl;

    return ;

}