#include <iostream>

using namespace std;

struct fraction
{ int top, bot; };

fraction add(fraction A, fraction B)
{ fraction R;
  R.top = A.top*B.bot + B.top*A.bot;
  R.bot = A.bot*B.bot;
  return R; }

fraction sub(fraction A, fraction B)
{ fraction R;
  R.top = A.top*B.bot - B.top*A.bot;
  R.bot = A.bot*B.bot;
  return R; }

fraction mul(fraction A, fraction B)
{ fraction R;
  R.top = A.top*B.top;
  R.bot = A.bot*B.bot;
  return R; }

fraction div(fraction A, fraction B)
{ fraction R;
  R.top = A.top*B.bot;
  R.bot = A.bot*B.top;
  return R; }

void print(fraction X)
{ if (X.top == 0)
    cout << "0"; 
  else if (X.bot == 1)
    cout << X.top;
  else
    cout << X.top << "/" << X.bot; }

int main()
{ while (true)
  { fraction a, b;
    cout << "Enter A's top and bottom: ";
    cin >> a.top >> a.bot;
    cout << "Enter B's top and bottom: ";
    cin >> b.top >> b.bot;

    cout << "A + B = ";
    print(add(a, b));
    cout << "\n";

    cout << "A - B = ";
    print(sub(a, b));
    cout << "\n";

    cout << "A * B = ";
    print(mul(a, b));
    cout << "\n";

    cout << "A / B = ";
    print(div(a, b));
    cout << "\n"; } }