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