a = list(map(int,input().split()))
for i in range(1,len(a),2):
if (a[i-1]<a[i]):
(a[i-1],a[i])=a[i],a[i-1]
print(a)
YSA9IGxpc3QobWFwKGludCxpbnB1dCgpLnNwbGl0KCkpKQpmb3IgaSBpbiByYW5nZSgxLGxlbihhKSwyKToKCWlmIChhW2ktMV08YVtpXSk6CgkJKGFbaS0xXSxhW2ldKT1hW2ldLGFbaS0xXQpwcmludChhKQ==