#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
LL p[15], q[15];
LL gcd(LL x, LL y)
{
    if(x == 0) return y; else return gcd(y % x, x);
}
int main()
{
    int n; scanf("%d", &n);
    for(int i = 1; i <= n; i++) scanf("%lld/%lld", &p[i], &q[i]);
    LL lcd = q[1]; for(int i = 2; i <= n; i++) lcd = lcd / gcd(lcd, q[i]) * q[i];
    LL sum = 0;   for(int i = 1; i <= n; i++) sum += p[i] * (lcd / q[i]);
    LL g = gcd(sum, lcd);
    sum /= g;
    lcd /= g;
    if(lcd == 1) printf("%lld\n", sum);
    else printf("%lld/%lld\n", sum, lcd);
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
LL p[15],q[15];
LL gcd(LL x,LL y)
{
	if(x==0) return y;else return gcd(y%x,x);
}
int main()
{
    int n;scanf("%d",&n);
    for(int i=1;i<=n;i++) scanf("%lld/%lld",&p[i],&q[i]);
    LL lcd=q[1];for(int i=2;i<=n;i++)lcd=lcd/gcd(lcd,q[i])*q[i];
	LL sum=0;   for(int i=1;i<=n;i++)sum+=p[i]*(lcd/q[i]);
	LL g=gcd(sum,lcd);
	sum/=g;
	lcd/=g;
	if(lcd==1) printf("%lld\n",sum);
	else printf("%lld/%lld\n",sum,lcd);
	return 0;
}