#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
using namespace std;

int main()
{
	int n;
	cin >> n;

	vector<int> gear;
	gear.resize(n);
	for (int i = 0; i < n; i++){
		cin >> gear[i];
	}

	cout << gear[n - 1] << '/' << gear[0] << endl;

	return 0;
}