N=input()
pt=[]
for i in range(len(N)):
    for j in range(i+1,len(N)):
        for k in range(j+1,len(N)):
            if N[i]!=N[j] and N[j]==N[k]:
                pt.append((i,j,k))
from copy import deepcopy
def ans(his,nu):
    if his.count(0)<3:
        return nu
    maximum=nu
    for i,j,k in pt:
        if all([his[i]==0,his[j]==0,his[k]==0]):
            his_c=deepcopy(his)
            his_c[i]=1;his_c[j]=1;his_c[k]=1
            maximum=max(maximum,ans(his_c,nu+int(N[i])*100+int(N[j])*11))
    return maximum
print(ans([0]*len(N),0))