# import sys; input = sys.stdin.buffer.readline
# sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")
import copy

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	S = list(input())
	N = len(S)
	L = [int("".join(S))]
	for i in range(N):
		for j in range(N):
			ll = copy.copy(S)
			ll[i], ll[j] = ll[j], ll[i]
			s = int("".join(ll))
			L.append(s)

	L.sort()
	print(L[-1])



if __name__ == '__main__':
	main()