X=sorted(input(),reverse=True)
if X[0]==X[-1] or X[1]=="0":
    print(-1)
else:
    for i in reversed(range(1,len(X))):
        if X[i]!=X[i-1]:
            X[i],X[i-1]=X[i-1],X[i]
            print("".join(X));exit()