/*
 * struct.cpp
 *
 *  Created on: 17.01.2013
 *      Author: trifon
 */

#include <iostream>
using namespace std;
#include <cstring>
#include <cstdlib>

struct Complex {
	double re, im;
};

struct Student {
	char name[100];
	int fn;
	double grade;
};

void printStudent(Student s)
{
	cout << s.name << ' ' << s.fn << ' ';
	cout << s.grade << endl;
	s.grade = 6;
}

Student chooseBetter(Student s1, Student s2)
{
	if (s1.grade > s2.grade)
		return s1;
	return s2;
}

int main1()
{
	cout << sizeof(Complex) << endl;
	cout << sizeof(Student) << endl;

	Complex z1, z2 = { 1.2, 3.4 };
	Student s1 = { "Иван Колев", 44444, 4.4 };

	cout << z2.im << endl;
	z1 = z2;
	cout << z1.re << endl;
	cin >> z2.im;
	cout << z2.im << endl;

	char str1[10] = "Hello", str2[10] = "Hi";
	char* pp = str1;
	cout << sizeof(str1) << ' ' << sizeof(pp) << endl;
	//!!!! str1 = str2;
	Student s2;
	s2 = s1;
	cout << s2.name << endl;
	int *p = &s1.fn;
	double *q = &s1.grade;
	char* s = s1.name;
	char* ss = s1.name + 5; // = &s1.name[5];
	// !!! лошо, но вярно:
	// !!! int* x = (int*)&s1.grade;
	// !!! cout << *x << endl;

	Student sa[10] =
		{ { "Иван Иванов", 80000, 5.5 },
		  { "Стефан Стефанов", 80001, 6 } };

	// sa[1] = sa[0]; // OK
	// !!! sa[2].name = "Петър Петров";
	strcpy(sa[2].name, "Петър Петров");

	for(int i = 0; i < 3; i++)
		cout << sa[i].fn << endl;

	struct FootballTeam
	{
		Student players[11];
		char name[100];
	};

	FootballTeam fteam = { { { "", 0, 0 } } };

	fteam.players[1].fn = fteam.players[4].fn;
	fteam.players[5] = fteam.players[3];
	strcpy(fteam.name, "The KNs");
	strcpy(fteam.players[10].name, "Петко");

	printStudent(s1);
	printStudent(s1);
	Student s3 = chooseBetter(sa[0], sa[1]);
	printStudent(s3);
	s3.grade = 3;
	printStudent(s3);
	printStudent(sa[1]);

	Student *ps1 = &s1, *ps2 = NULL;
	printStudent(*ps1);

	char* pp1 = s1.name;
	cout << ps1 << ' ' << (void*)pp1 << endl;
	// лошо
	char* pp2 = (char*)ps1;
	cout << pp2 << endl;

	*ps1 = sa[1]; // <-> s1 = sa[1];
	printStudent(s1);

	Student& s4 = s1;
	s4.grade = 5;
	printStudent(s1);

	cout << (*ps1).name << endl;
	// !!! *ps1.name <-> *(ps1.name)
	ps1->grade += 0.5;
	// <-> (*ps1).grade += 0.5;
	// <-> s1.grade += 0.5;

	struct Employee {
		char name[100];
		Employee* boss;
	};

	Employee rector = { "Илчев", NULL },
		dean = { "Сосков", &rector },
		chair = { "Димитров", &dean },
		assistant = { "Трифонов", &chair };

	cout << assistant.name << endl
		 << assistant.boss->name << endl
		 << assistant.boss->boss->name << endl
		 << assistant.boss->boss->boss->name << endl;

	cout << (void*)assistant.boss->boss->boss->boss
			<< endl;

	Employee* pe = &assistant;
	while (pe != NULL)
	{
		cout << pe->name << endl;
		pe = pe->boss;
	}

	return 0;
}

const int MAX = 100;

int readStudents(Student s[]) {
	int count = 0;
	do {
		cin >> s[count].fn;
		if (s[count].fn >= 0) {
			cin >> s[count].grade;
			cin.getline(s[count].name, MAX);
		}
		count++;
	} while(s[count-1].fn >= 0);
	// s[count-1].fn < 0
	return count-1;
}

void printStudentsTable(Student s[], int n) {
	for(int i = 0; i < n; i++) {
		cout << s[i].fn << '\t' << s[i].grade << '\t';
		cout << s[i].name << endl;
	}
}

double averageGrade(Student s[], int n) {
	double sum = 0;
	for(int i = 0; i < n; i++)
		sum += s[i].grade;
	return sum / n;
}

void arrangeStudents(Student s[], int n) {
	for(int i = 0; i < n - 1; i++) {
		// сортираната част е от
		// 0 до i-1 включително
		// намираме студента с най-малък Ф№
		// и го разменяме с s[i]
		int min = i;
		for(int j = i + 1; j < n; j++) {
			if (s[j].fn < s[min].fn) {
				min = j;
			}
		}
		// разменяме s[i] със s[min]
		Student tmp = s[i];
		s[i] = s[min];
		s[min] = tmp;
		// Сортираната част е от 0 до i вкл.
	}
}

void arrangeStudentsGrade(Student s[], int n) {
	for(int i = 0; i < n - 1; i++) {
		// сортираната част е от
		// 0 до i-1 включително
		// намираме студента с най-малък Ф№
		// и го разменяме с s[i]
		int max = i;
		for(int j = i + 1; j < n; j++) {
			if (s[j].grade > s[max].grade) {
				max = j;
			}
		}
		// разменяме s[i] със s[min]
		Student tmp = s[i];
		s[i] = s[max];
		s[max] = tmp;
		// Сортираната част е от 0 до i вкл.
	}
}

bool isLessByFn(Student s1, Student s2)
{
	return s1.fn < s2.fn;
}

bool hasBetterGrade(Student s1, Student s2)
{
	return s1.grade > s2.grade;
}

void arrangeStudentsGeneral(Student s[], int n,
		     bool (*isLess)(Student,Student)) {
	for(int i = 0; i < n - 1; i++) {
		// сортираната част е от
		// 0 до i-1 включително
		// намираме "минималния" студент
		// и го разменяме с s[i]
		int min = i;
		for(int j = i + 1; j < n; j++) {
			if (isLess(s[j],s[min])) {
				min = j;
			}
		}
		// разменяме s[i] със s[min]
		Student tmp = s[i];
		s[i] = s[min];
		s[min] = tmp;
		// Сортираната част е от 0 до i вкл.
	}
}


int main2()
{
	Student students[MAX];
	int n = readStudents(students);
	cout << "Прочетени " << n << " студента" << endl;
	printStudentsTable(students, n);
	cout << "Среден успех: " <<
		averageGrade(students, n) << endl;
	arrangeStudentsGeneral(students, n, isLessByFn);
	printStudentsTable(students, n);
	arrangeStudentsGeneral(students, n, hasBetterGrade);
	printStudentsTable(students, n);

	return 0;
}

int gcd(int x, int y) {
	if (x == y)
		return x;
	if (x > y)
		return gcd(x - y, y);
	return gcd(x, y - x);
}

struct Rational {
	int numer, denom;
};

Rational createRational(int n, int d) {
	if (d == 0) {
		cerr << "Деление на 0!";
		exit(1);
	}
	int g = gcd(n, d);
	n /= g;
	d /= g;
	Rational r = { n, d };
	// r.numer = n; r.denom = d;
	return r;
}

int getNumerator(Rational r) {
	return r.numer;
}

int getDenominator(Rational r) {
	return r.denom;
}

Rational addRational(Rational r1, Rational r2) {
	return createRational(
			getNumerator(r1) * getDenominator(r2) +
			getNumerator(r2) * getDenominator(r1),
			getDenominator(r1) * getDenominator(r2));
}

Rational subtractRational(Rational r1, Rational r2) {
	return createRational(
			getNumerator(r1) * getDenominator(r2) -
			getNumerator(r2) * getDenominator(r1),
			getDenominator(r1) * getDenominator(r2));
}

Rational multRational(Rational r1, Rational r2) {
	return createRational(
			getNumerator(r1) * getNumerator(r2),
			getDenominator(r1) * getDenominator(r2));
}

Rational divRational(Rational r1, Rational r2) {
	return createRational(
			getNumerator(r1) * getDenominator(r2),
			getDenominator(r1) * getNumerator(r2));
}

void printRational(Rational r) {
	cout << getNumerator(r) << '/' << getDenominator(r);
}

Rational readRational() {
	int n, d;
	cin >> n >> d;
	return createRational(n, d);
}

int main()
{
	Rational r1 = readRational(), r2 = readRational();
	Rational r = addRational(r1, r2);
	printRational(r);
	return 0;
}