#include<bits/stdc++.h>
#define vint vector<int>
#define vstr vector<string>
#define vll vector<long long>
#define ll long long
#define pf printf
#define sf scanf
#define sfd(n) scanf("%d", &n)
#define sflf(n) scanf("%lf", &n)
#define sfll(n) scanf("%lld", &n)
#define pfd(n) printf("%d", n)
#define pflf(n) printf("%lf", n)
#define pfll(n) printf("%lld", n)
#define pft printf("\t")
#define pfn printf("\n")
#define pfk printf(" ")
#define PI 3.1415926
#define MAX 200020
#define M 1e18
#define F -1e6
#define E 1e6
using namespace std;
/*
ll gcd(int a, int b) {
if( b==0 ) {
return a;
}
return gcd(b, a%b);
}
*/
int main() {
int n;
cin >> n;
ll a, b, c, d;
if( n>0 ) {
sf("%lld/%lld", &c, &d);
for( int i=1; i<n; i++ ) {
// pf("%lld/%lld", c, d);
// pfn;
sf("%lld/%lld", &a, &b);
ll e = d/__gcd(b, d)*b;
c = e/d*c+e/b*a;
d = e;
}
int f = 1;
if( c<0 ) {
f = 0;
c = -c;
}
ll e = __gcd(c, d);
c = c/e;
d = d/e;
ll g = c/d;
c = c%d;
if( f==0 ) {
g = -g;
c = -c;
}
if( g ) {
pfll(g);
}
if( c ) {
if( g ) pfk;
pf("%lld/%lld", c, d);
}
if( !g&&!c ) {
pfd(0);
}
}else {
pfd(0);
}
return 0;
}
PS:还是不懂自己的gcd比__gcd不行。