ds = [int(d) for d in input()]
max_d = max(ds)
for i, d in enumerate(ds[::-1], 1):
    if d == max_d:
        second = len(ds) - i
        break
first = second
for i, d in enumerate(ds):
    if d < max_d:
        first = i
        break
if first < second:
    ds[first], ds[second] = ds[second], ds[first]
print(''.join(map(str, ds)))