import sys
input = sys.stdin.readline
def read_values(): return tuple(map(int, input().split()))
def read_list(): return list(map(int, input().split()))

class PalindromicTree:
    def __init__(self):
        self.st=[]
        self.length=[-1,0]
        self.parent=[0,0]
        self.count=[0,0]
        self.link=[dict() for _ in range(2)]
        self.lastNodeIdx=0
        
    def add(self,v):
        self.st.append(v)
        prevNodeIdx=self.lastNodeIdx
        nextNodeIdx=self.lastNodeIdx
        while True:
            head = self.length[nextNodeIdx] + 2
            if head <= len(self.st) and self.st[-head]==self.st[-1]:
                break
            nextNodeIdx=self.parent[nextNodeIdx]
        nextLen=self.length[nextNodeIdx]+2
        if v in self.link[nextNodeIdx].keys():
            self.lastNodeIdx=self.link[nextNodeIdx][v]
            self.count[self.lastNodeIdx]+=1
            return
        self.lastNodeIdx=len(self.length)
        self.length.append(nextLen)
        if self.length[-1]==1:
            self.parent.append(1)
        else:
            prevNodeIdx=self.parent[nextNodeIdx]
            while True:
                head = self.length[prevNodeIdx] + 2
                if head <= len(self.st) and self.st[-head]==self.st[-1]:
                    break
                prevNodeIdx=self.parent[prevNodeIdx]
            self.parent.append(self.link[prevNodeIdx][v])
        self.count.append(1)
        self.link[nextNodeIdx][v]=self.lastNodeIdx
        self.link.append(dict())

def main():  
    s=input()
    pt = PalindromicTree()
    for i in range(len(s)-1):
        pt.add(s[i])
    nodeCount = len(pt.length)
    count=[0]*nodeCount
    for i in range(nodeCount):
        node=i
        while node>1:
            count[node]+=pt.count[i]
            node=pt.parent[node]
    score=[-1]*nodeCount
    score[0]=0
    score[1]=0
    for i in range(nodeCount):
        if score[i]!=-1:
            continue
        stk=[i]
        while score[stk[-1]]==-1:
            stk.append(pt.parent[stk[-1]])
        tmp=score[stk[-1]]
        stk.pop()
        for v in stk[::-1]:
            tmp+=pt.length[v]*count[v]
            score[v]=tmp
    print(max(score))
            
if __name__ == "__main__":
    main()