#include<stdio.h>
#include<math.h>
int main()
{
	int a, b,c,d;
	scanf_s("%d/%d", &a, &b);
	int gcd(int a, int b);
	while (scanf_s("%d/%d",&c,&d) != 0)
	{
		a = a * d + b * c;
		b = b * d;
	}
	int e = gcd(a, b);
	if (e == -1)
	{
		printf("0");
		return 0;
	}
	else
	{
		a = a / e;
		b = b / e;
	}
	printf("%d/%d", a, b);
	return 0;
}
int gcd(int a, int b)                   //约分函数，辗转相除法
{
	if (a == 0)
	{
		return -1;
	}
	int c = a % b;
	while (c != 0)
	{
		a = b;
		b = c;
		c = a % b;
	}
	return abs(b);                   
}