#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll gcd(ll a,ll b){
	if(b>a)	swap(a,b);
	while(a%b!=0){
		ll tmp=a%b;
		a=b,b=tmp;
	}
	return b;
}
int main(){
	int n;	cin>>n;
	ll z[n];
	for(int i=0;i<n;i++)	cin>>z[i];
	ll a=z[0],b=z[n-1];
	cout<<b<<"/"<<a<<endl;
	return 0;
}