#!/usr/bin/env python3

START = "ALICE"
END = "BOBER"

def main():
    nodes = {} # vrchol : [ hrany ]
    for _ in range(int(input())): # nacitani vstupu
        x, y = input().split('-')
        if not x in nodes.keys(): nodes[x] = []
        if not y in nodes.keys(): nodes[y] = []
        nodes[x].append(y)
        nodes[y].append(x)

    for k in nodes.keys():
        nodes[k].sort() # utridime sousedy kazdeho vrcholu

    visited = set() # navstivene vrcholy
    
    def dive(node): # rekurzivni zanoreni
        if node == END: return [node]   # nasli sme reseni, vracime obracenou cestu
        if node in visited: return None # preskakujeme uz navstiveny vrchol
        
        # navstevujeme novy vrchol
        visited.add(node)

        for n in nodes[node]:    # postupne zkusime navstivit vsechny sousedy
            ans = dive(n)
            if ans is not None:  # jestli sme nasli reseni
                ans.append(node) # pridame do cesty aktualni vrchol
                return ans       # a propagujeme nalez dal
            
    print("->".join(reversed(dive(START)))) # vypiseme obracenou cestu v spravnem poradi

main()