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

int main(){
	int n;
	cin >> n;
	vector<long long int> z(n);
	for(auto &a:z) cin >> a;
	printf("%lld/%lld\n",z[n-1],z[0]);
	//	cout << z[n-1] << "/" << z[0] << endl;
	return 0;
}