#include <bits/stdc++.h>
#define rep(i, a) rep2 (i, 0, a)
#define rep2(i, a, b) for (int i = (a); i < (b); i++)
#define repr(i, a) repr2 (i, 0, a)
#define repr2(i, a, b) for (int i = (b) - 1; i >= (a); i--)
#define chmin(a, b) ((b) < a && (a = (b), true))
#define chmax(a, b) (a < (b) && (a = (b), true))
#define rng(a) (a).begin(), (a).end()
using namespace std;
typedef long long ll;

int main() {
	int n;
	cin >> n;
	vector<ll> z(n);
	rep (i, n) cin >> z[i];
	cout << z.back() << "/" << z.front() << endl;
}