import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import itertools

N = [x - ord('0') for x in read().rstrip()]

def F(N):
    items = len(N)
    best = 0
    for i,j,k in itertools.combinations(range(items), 3):
        if not (N[i] != N[j] == N[k]):
            continue
        A = [x for ind, x in enumerate(N) if ind not in [i,j,k]]
        x = F(A) + N[i] * 100 + N[j] * 11
        if best < x:
            best = x
    return best

print(F(N))