n = map(int,raw_input())
m = sorted(n,reverse=True)
a,b = -1,0
for i in range(len(n)):
	if a == -1 and n[i] != m[i]:
		a = i
	if n[i] == m[a]:
		b = i
n[a], n[b] = n[b], n[a]
print "".join(map(str,n))