class Node:
    def __init__(self, data):
        self.data = data
        self.prev = None
        self.next = None

class Playlist:
    def __init__(self):
        self.head = None
        self.tail = None

    def add_song(self, title):
        # Check for invalid input
        if not title.isalpha():
            return False
        
        new_node = Node(title)
        if self.head is None:
            self.head = new_node
            self.tail = new_node
        else:
            self.tail.next = new_node
            new_node.prev = self.tail
            self.tail = new_node
        return True

    def search_prefix(self, prefix):
        current = self.head
        found = False
        while current:
            if current.data.startswith(prefix):
                print(current.data)
                found = True
            current = current.next
        if not found:
            print("No song found")

# Input handling
try:
    n = int(input())
    playlist = Playlist()
    valid_input = True
    for _ in range(n):
        title = input().strip()
        if not playlist.add_song(title):
            valid_input = False
    prefix = input().strip()

    if not valid_input:
        print("Invalid input")
    else:
        playlist.search_prefix(prefix)
except:
    print("Invalid input")