import collections

x = int(input())

x_list = list(str(x))
sorted_x = sorted(x_list, reverse=True)
clc = collections.Counter(sorted_x)
num_clc = len(clc.keys())

if num_clc == 1:
    res = -1
else:
    swap_index = sorted_x.index(min(sorted_x))
    sorted_x[swap_index], sorted_x[swap_index - 1] = \
    sorted_x[swap_index - 1], sorted_x[swap_index]
    
    if sorted_x[0] == 0:
        res = -1
    else:
        res = ''.join(sorted_x)
        
print(res)