#define _USE_MATH_DEFINES
#include<stdio.h>
#include<string>
#include<iostream>
#include<cctype>
#include<cstdio>
#include<vector>
#include<stack>
#include<queue>
#include <algorithm>
#include<math.h>
#include<set>
#include<map>
#include<iomanip>

//#include<bits/stdc++.h>



using namespace std;

long h(long w){
	if(w%2==0)return w/2;
	for(long i=3;i*i<=w;i+=2)if(w%i==0)return w/i;
	return 1;
}


int main() {
	
	long long int a,b;
	int n;
	cin>>n;
	for(int i=0;i<n;i++){
		long long int r;
		cin>>r;
		if(!i)a=r;
		if(i==n-1)b=r;
	}
	cout<<b<<'/'<<a<<endl;
	
	return 0;
}