#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <math.h>

using namespace std;
int main()
{
	int n;
	cin >> n;
	vector<long long> gearList;
	for(int i = 0; i < n; i++)
	{
		long long gear;
		cin >> gear;
		gearList.push_back(gear);
	}

	cout << gearList[n-1] << '/' << gearList[0];
	return 0;
}