X=sorted([int(s) for s in list(input())])
X_set=sorted(list(set(X)))
if len(X_set)==1 or (len(X_set)==2 and X_set[0]==0 and  X.count(X_set[1])==1):
    print(-1)
else:
    for i in range(1,len(X)):
        if X[i]!=X[i-1]:
            a=0
            a+=X[i]
            b=0
            b+=X[i-1]
            X[i]=b
            X[i-1]=a
            break
    ans=""
    for i in range(len(X)):
        ans+=str(X[len(X)-i-1])
    print(ans)