S = raw_input()
ds = [int(x) for x in S]
dmax = max(ds)
dmin = min(ds)
argmax = len(ds) - 1
while ds[argmax] != dmax:
    argmax -= 1
argmin = 0
while ds[argmin] != dmin:
    argmin += 1
if argmin < argmax:
    ds[argmin] = dmax
    ds[argmax] = dmin
print(''.join([str(x) for x in ds]))