#include<cstdio>
#include<iostream>
#include<algorithm>
#include<string>
#include<queue>
#include<vector>
#include<functional>
#include<cmath>
#include<map>
#include<stack>
#include<set>
#include<numeric>
#include<limits>

using namespace std;
typedef long long ll;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;

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

	ll z[51];

	for (int i = 0; i < N; i++) {
		cin >> z[i];
	}

	printf("%lld/%lld\n",z[N-1],z[0]);

	return 0;
}