#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

long long gcd(long long m, long long n)
{
    while(m && n) if (m < n) n %= m; else m %= n;
    return m + n;
}

int main ()
{
    int num;
    long long n, d, s, p;
    scanf("%d", &num);
    scanf("%lld/%lld",&s,&p);
    assert(p != 0);

    for (int i = 1; i < num; i++)
    {
        scanf("%lld/%lld", &n, &d);
        assert(d != 0);
        s = s*d + n*p;
        p *= d;
        long long g = gcd(s,p);
        s /= g;
        p /= g;
    }
    printf ("%lld/%lld\n", s, p);
}