n = list(map(int, list(input())))
n_max = max(n)
n_max_index = len(n) - n[::-1].index(n_max) - 1

for i in range(n_max_index):
	if n[i] == n_max: continue
	n[i], n[n_max_index] = n[n_max_index], n[i]
	break

for i in n:
	print(i, end='')
print()