#include<bits/stdc++.h> using namespace std; int s[11],t[11]; char a[11]; int main() { int n,h=t[0],j=1; double sum=0; cin>>n; for(int i=0;i<n;++i){ cin>>s[i]>>a[i]>>t[i]; sum+=1.0*s[i]/t[i]; h=__gcd(h,t[i]); j*=t[i]; } cout<<j/h*sum<<"/"<<j/h; return 0; }