N = input().rstrip()

MAX = 0
def dfs(score, N):
    global MAX
    MAX = max(MAX, score)

    for i in range(len(N)):
        for j in range(i + 1, len(N)):
            for k in range(j + 1, len(N)):
                if N[j] == N[k] and N[i] != N[j] and N[i] != '0':
                    x = int(N[i]) * 100 + int(N[j]) * 11
                    l = N[:k] + N[k + 1:]
                    m = l[:j] + l[j + 1:]
                    n = m[:i] + m[i + 1:]
                    dfs(score + x, n)

dfs(0, N)
print(MAX)