#include <iostream>
#include <string>
#include <vector>
#include <cstring>
#include <climits>
#include <algorithm>
#include <map>
using namespace std;

int main() {
    int N;
    cin >> N;
    vector<int> z(N);
    for (int i=0; i<N; ++i) {
        cin >> z[i];
    }
    cout << z[0] << "/" << z[N-1] << endl;
    return 0;
}