class UnionFind:
    def __init__(self):
        self.parent = {}

    def root(self, name):
        if self.parent[name] == name:
            return name
        else:
            self.parent[name] = self.parent[self.parent[name]] 
            return self.root(self.parent[name])

    def unite(self, a, b):
        if a not in self.parent:
            self.new_node(a)

        if b not in self.parent:
            self.new_node(b)

        a_root = self.root(a)
        b_root = self.root(b)
        self.parent[a_root] = b_root

    def new_node(self, node):
        self.parent[node] = node

    def roots(self):
        return [name for name, parent in self.parent.items() if parent == name]
            

if __name__ == '__main__':
    union_find = UnionFind()

    n = int(input())
    for i in range(n):
        a, b = input().split(' ')
        union_find.unite(a, b)

    print('\n'.join(union_find.roots()))