x = input()
y = sorted(x, reverse=True)
if y[0]==y[-1]:
    print(-1)
else:
    for i in range(1, len(y)):
        if y[-1] != y[-1-i]:
            y[-1-i], y[-i] = y[-i], y[-i-1]
            break
    if y[0] == '0':
        print(-1)
    else:
        print(''.join(y))