MOD = 10 ** 9 + 7
INF = 10 ** 10
import sys
sys.setrecursionlimit(100000000)
dy = (-1,0,1,0)
dx = (0,1,0,-1)

def main():
    x = input()
    cnt = [0] * 10
    num = '0123456789'

    for i in x:
        for j in range(10):
            if num[j] == i:
                cnt[j] += 1
                break

    a,b = -1,-1
    for i in range(1,10):
        if cnt[i] > 0:
            if a < 0:
                a = i
            else:
                b = i
                break
    if b < 0:
        print(-1)
        return

    ans = []
    for i in range(10):
        if i == a:
            ans.append(num[b] + num[a] * (cnt[a] - 1))
        elif i == b:
            ans.append(num[b] * (cnt[b] - 1) + num[a])
        else:
            ans.append(num[i] * cnt[i])
    
    print(''.join(ans[::-1]))

if __name__ =='__main__':
    main()