x=list(input())

if len(set(x))==1: # 999
    print(-1)
    exit()

flg=True
for i in range(1,len(x)):
    if x[i] != "0":
        flg=False
if flg:
    print(-1)
    exit()
x.sort()
for i in range(1,len(x)):
    if x[0] != x[i]:
        x[0],x[i] = x[i],x[0]
        break
x=list(reversed(x))
print(*x,sep="")