#include<bits/stdc++.h>
typedef long long ll;
using namespace std;
int INF = 1e9;
int MOD = 1e9+7;
main(){
    ll N,A[50];
    cin >> N;
    for(int i = 0;i < N;i++)cin >> A[i];
    cout << A[N-1] << "/" << A[0] << endl;
}