import sys

x=int(sys.argv[1])
y=int(sys.argv[2])
z=int(sys.argv[3])
cuplet=str
add=str
song=str
i=int(0)
q=int(0)
cuplet='la'
add='-la'

if x == 0:
        cuplet=''
elif x == 1:
        cuplet=cuplet
else:
        while i < (x-1):
            cuplet=cuplet+add
            i=i+1
song=''

while q < y:
    song=song+(' '+cuplet)
    q=q+1

if z == 1:
    if x == 0 or y == 0:
        print 'Everybody sing a song:!'
    else:
        print 'Everybody sing a song:'+song+'!'
elif z == 0:
    if x == 0 or y == 0:
        print 'Everybody sing a song:.'
    else:
        print 'Everybody sing a song:'+song+'.'