import sys
sys.setrecursionlimit(10 ** 9) #再帰回数の限界を変更
ans = 0
def dfs(A,v):
    global ans
    if len(A) < 3:
        return
    for i in range(len(A)):        
        for j in range(i+1,len(A)):
            for k in range(j+1,len(A)):
                if A[i]!=0 and A[i]!=A[j] and A[j]==A[k]:
                    ans = max(v+A[i]*100+A[j]*11,ans)
                    AD = []
                    for m in range(len(A)):
                        if m!=i and m!=j and m!=k:
                            AD.append(A[m])
                    dfs(AD,v+A[i]*100+A[j]*11)

N = list(input())
L = []
for n in N:
    L.append(int(n))
dfs(L,0)
print(ans)