Rational Sum (20) 水

#include<bits/stdc++.h>
using namespace std;

#define debug puts("YES");
#define rep(x,y,z) for(int (x)=(y);(x)<(z);(x)++)
#define ll long long
#define ull unsigned long long

#define lrt int l,int r,int rt
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
#define root l,r,rt
#define mst(a,b) memset((a),(b),sizeof(a))
#define pii pair<int,int>
#define piii pair<int,pii>
#define fi first                                  
#define se second
#define mk(x,y) make_pair(x,y)

#define base 2333
const int mod=1e9+7;
const int maxn=100+10;
const int ub=1e6;
ll powmod(ll x,ll y){ll t; for(t=1;y;y>>=1,x=x*x%mod) if(y&1) t=t*x%mod; return t;}
ll gcd(ll x,ll y){
    if(y==0) return x;
    return gcd(y,x%y);
}
int n,v=1,tot=0;
int x[maxn],y[maxn];
int main(){
    scanf("%d",&n);
    rep(i,0,n){
        scanf("%d/%d",&x[i],&y[i]);
        v=v*y[i]/gcd(v,y[i]);
    }
    rep(i,0,n){
        x[i]*=(v/y[i]);
        tot+=x[i];
    }
    int gd=gcd(tot,v);
    tot/=gd,v/=gd;
    if(v<0) v=-v,tot=-tot;
    if(tot){
        if(tot/v) printf("%d ",tot/v);
        if(tot%v) printf("%d/%d\n",tot%v,v);
    }
    else puts("0");
    return 0;
}