#include<fstream>
using namespace std;
ifstream fin("date.in");
ofstream fout("date.out");

struct rational {int nr, nu;};

int cmmdc(int a, int b)
{
    if (a % b == 0) return b;
    else return cmmdc(b, a % b);
}

void simplific(rational &r)
{
    int c = cmmdc(abs(r.nr), abs(r.nu));
    r.nu = r.nu / c;
    r.nr = r.nr / c;
	if(r.nr*r.nu<0)
	{
		r.nu=abs(r.nu);
		r.nr=-abs(r.nr);
	}
	else
	{
		r.nu=abs(r.nu);
		r.nr=abs(r.nr);
	}
}

void citire(rational &r)
{
	fin>>r.nr>>r.nu;
	simplific(r);
}

void afisare(rational r)
{
	fout<<r.nr<<"/"<<r.nu<<" ";
}

rational adunare(rational x, rational y)
{
    int a = x.nr * y.nu + x.nu * y.nr;
	int b = x.nu * y.nu;
	rational r;
	r.nr=a; r.nu=b;
	simplific(r);
	return r;
}

int main()
{
	int n,i;
	rational a,s;
	fin>>n;
	citire(a);
	s=a;
	for(i=2;i<=n;i++)
	{
		citire(a);
		s=adunare(s,a);;
	}
	afisare(s);
	fin.close();
	fout.close();
	return 0;
}