#include <iostream>

using namespace std;

struct fraction
{ int top, bot; };

int gcd(int a, int b)
// There is a much better (faster) method than this. It is called
// Euclid's Algorithm. You might want to look it up. We stuck with
// this slow version because it doesn't require any knowledge that
// you can't be expected to have yet.
{ for (int i = max(a, b); i >= 1; i -= 1)
    if (a % i == 0 && b % i == 0)
      return i;
  return 1; }

void correct(fraction & f)
{ int d = gcd(f.top, f.bot);
  f.top /= d;
  f.bot /= d; }

void set(fraction & f, int t, int b)
{ f.top = t;
  f.bot = b;
  correct(f); }

void print(fraction f)
{ cout << f.top << "/" << f.bot; }

fraction add(fraction x, fraction y)
{ fraction R;
  set(R, x.top * y.bot + y.top * x.bot, x.bot * y.bot);
  correct(R);
  return R; }

fraction subtract(fraction x, fraction y)
{ fraction R;
  set(R, x.top * y.bot - y.top * x.bot, x.bot * y.bot);
  correct(R);
  return R; }

fraction multiply(fraction x, fraction y)
{ fraction R;
  set(R, x.top * y.top, x.bot * y.bot);
  correct(R);
  return R; }

fraction divide(fraction x, fraction y)
{ fraction R;
  set(R, x.top * y.bot, x.bot * y.top);
  correct(R);
  return R; }

bool less(fraction x, fraction y)
// just an example, there would be a number of different comparing functions.
{ return x.top * y.bot < y.top * x.bot; }

int main()
{ fraction A, B;
  set(A, 1, 2);   // A = 1/2;
  set(B, 3, 4);   // B = 3/4
  fraction C = add(A, B);
  print(C);
  cout << "\n"; }