#include <bits/stdc++.h>
using namespace std;
#define int long long   // <-----!!!!!!!!!!!!!!!!!!!

#define rep(i,n) for (int i=0;i<(n);i++)
#define rep2(i,a,b) for (int i=(a);i<(b);i++)
#define rrep(i,n) for (int i=(n)-1;i>=0;i--)
#define rrep2(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define all(a) (a).begin(),(a).end()

typedef long long ll;
typedef pair<int, int> P;
typedef vector<int> V;
typedef vector<vector<int>> VV;

signed main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);

    int N;
    cin >> N;
    vector<int> z(N);
    rep(i, N) cin >> z[i];
    cout << z[N-1] << "/" << z[0] << endl;

}