x = input()
 
sorted_x = sorted(x, reverse=True)
 
xs = []
for c in sorted_x:
    if c == '0': continue
    xs.append(c)
 
ans = '-1'
 
if len(xs) < 2:
    print(ans)
    exit()
 
for i in range(len(x)-1, 0, -1):
    c1 = sorted_x[i]
    c2 = sorted_x[i-1]
    if c1 != c2:
        list = sorted_x[:i-1]
        list.append(c1)
        list.append(c2)
        list += sorted_x[i+1:]
        break
 
ans = ''.join(list)
 
print(ans)