# Xoa khoang trang dau, cuoi, giua
def ToiUuChuoi(s):
s2=s
s2=s.strip()
arr=s2.split(' ')
s2=""
for x in arr:
word=x
if len(word.strip())!=0:
s2=s2+word+" "
return s2.strip()
s=input("String:")
s=ToiUuChuoi(s)
print(s)
IyBYb2Ega2hvYW5nIHRyYW5nIGRhdSwgY3VvaSwgZ2l1YQpkZWYgVG9pVXVDaHVvaShzKToKICAgIHMyPXMKICAgIHMyPXMuc3RyaXAoKQogICAgYXJyPXMyLnNwbGl0KCcgJykKICAgIHMyPSIiCiAgICBmb3IgeCBpbiBhcnI6CiAgICAgICAgd29yZD14CiAgICAgICAgaWYgbGVuKHdvcmQuc3RyaXAoKSkhPTA6CiAgICAgICAgICAgIHMyPXMyK3dvcmQrIiAiCiAgICByZXR1cm4gczIuc3RyaXAoKQoKcz1pbnB1dCgiU3RyaW5nOiIpCnM9VG9pVXVDaHVvaShzKQpwcmludChzKQ==