//走读的学姐→w←
#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
using namespace std;
char s[1100000];  int n;
long long f[1100000];
int main(){
	//freopen("ddd.in","r",stdin);
	freopen("savemzx.in","r",stdin);
	freopen("savemzx.out","w",stdout);
	scanf("%s",s+1);  n=strlen(s+1);
	f[1]=1;
	for(long long i=2;i<=n;i++){
		if(s[i]!=s[1])  f[i]=i*i;
		else{
			long long temp=1;
			while(s[i]==s[temp] && i<=n){
				f[i]=(i-temp)*(i-temp)+f[temp];
				temp++,i++;
			}
		}
	}
	//for(int i=1;i<=n;i++)  cout<<f[i]<<" ";
	sort(f+1,f+n+1);
	cout<<f[n]+f[n-1]<<endl;
	return 0;
}