tree_v1

#!/bin/python


def rem(keyToBeSearched, tree):
	# print "calling"
	for key,val in tree.items():
		if key == keyToBeSearched:
			# print "found", keyToBeSearched
			tree.pop(key, None)
			global branch
			branch = val
			return True
		else:
			rem(keyToBeSearched,val)

def insert(n1,n2,tree,orginalTree):
	global branch
	if n2 in tree:
		# print "inserted1",n1,n2
		d1 		= {n1:{}}
		rem(n1,orginalTree)
		# global branch
		if branch != None and len(branch):
			d1 = branch
			branch = None
		tree[n2] = dict(tree[n2].items() + d1.items())
		return True
	elif n1 in tree:	
		# print "inserted2"
		d1 		= {n2:{}}
		rem(n2,orginalTree)
		# global branch
		if branch != None and len(branch):
			d1 = branch
			branch = None
		tree[n1] = dict(tree[n1].items() + d1.items())
		return True
	else:
		for key,val in tree.items():
			if insert(n1,n2,val,orginalTree):
				return True

	return False



def countValues(key,count,tree):
	print "\'"+key+"\'", count
	for key,val in tree.items():
		countValues(key,count + len(tree),val)
		# print "count: ",count, " tree: ",tree

	return count	

tree = {}
branch = None

t = int(raw_input().strip())
for a0 in xrange(t):
    n1, n2 = raw_input().strip().split(' ')
    if not (insert(n1,n2,tree,tree)):
    	d1 		= {n1:{}}
    	d2 		= {n2:d1}
    	tree 	= dict(tree.items() + d2.items()) 
	# print "--->",tree

print "-----------------------"
print tree    
# print countValues('',0,tree)