from itertools import combinations

n = input()

def is_cww(i, j, k):
    return i != '0' and i != j and j == k

max_score = 0

while len(n) >= 3:
    max_cww = 0
    mi, mj, mk = 0, 0, 0
    for i, j, k in combinations(range(len(n)), 3):
        c, w1, w2 = n[i], n[j], n[k]
        if is_cww(c, w1, w2):
            cww = int(c + w1 + w2)
            if cww >= max_cww:
                max_cww = cww
                mi, mj, mk = i, j, k

    if max_cww == 0:
        break

    max_score += max_cww
    n = ''.join([n[l] for l in range(len(n)) if l != mi and l != mj and l != mk])

print(max_score)