def f(mask):
    sum = tmp = 0
    for i in range(dgt):
        if N[i] == '0':
            continue
        for j in range(i+1, dgt):
            for k in range(j+1, dgt):
                if N[i] == N[j] or N[j] != N[k]:
                    continue
                if mask & (1<<i | 1<<j | 1<<k):
                    continue
                tmp = int(N[i]) * 100 + int(N[j]) * 10 + int(N[k]) + f(mask | (1<<i | 1<<j | 1<<k))
                sum = max(sum, tmp)
    return sum
N = input()
dgt = len(N)
print(f(0))