X=input()
x=[0]*10
low2=10
low=10
for i in reversed(range(10)):
    x[i]=X.count(str(i))
    if x[i]>0:
        low2=low
        low=i
if len(X)-x[0]<=1 or low2==10:
    print(-1)
else:
    for i in reversed(range(10)):
        if x[i]==0: continue
        if i==low2:
            print(str(i)*(x[i]-1)+str(low),end='')
        elif i==low:
            print(str(low2)+str(i)*(x[i]-1),end='')
        else:
            print(str(i)*(x[i]),end='')