N = list(input())

max_n = max(N)
max_idx = 0
for i, n in enumerate(N):
    if n == max_n:
        if max_idx < i:
            max_idx = i

for i, n in enumerate(N):
    if n < max_n and i < max_idx:
        N[i], N[max_idx] = N[max_idx], N[i]
        break

print(''.join(N))