L=len
R=raw_input
a=[R()]
_=L(a[0])
while _>1-L(a):
	try:i=R();_=max(L(i)-L(a),_);a+=[i]
	except:R=0
	_-=1;print'  '*abs(_)+'___'.join([(l+'_'*99)[_+i]for i,l in enumerate(a)if _+i>=0]).rstrip('_').replace('_',' ')