import java.io.*; import java.util.*; class Main { public static void out (Object o) { System.out.println(o); } public static void main (String[] args) throws IOException { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); int n = Integer.parseInt(br.readLine()); String[] line = br.readLine().split(" "); out(line[n - 1] + "/" + line[0]); } }