#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)

typedef long long ll;
typedef vector<ll> vl;

int main()
{
	int N; cin >> N;
	vl z(N); rep(i, 0, N) cin >> z[i];

	cout << z[N - 1] << "/" << z[0] << endl;
}