import math
import copy

s = list(input())
ls = len(s)

def swap(a,b,c):
    x = copy.deepcopy(c)
    x[a], x[b] = x[b], x[a]
    return x 

swplist = [ [ (i,j) for j in range(i+1,ls) ]  for i in range(ls)]

stringlist = ["".join(s)]

for i in range(len(swplist)):
    for j in range(len(swplist[i])):
        b, e = swplist[i][j][0], swplist[i][j][1]
        stringlist.append("".join(swap(b,e,s)))

anslist = sorted(stringlist)
print(anslist[-1])