#include <bits/stdc++.h>
using namespace std;
const long long INF = 1e5+10;
char str[INF];
long long f[INF], m;
bool yz(long long start, long long end);
int main(){
	scanf("%s", str);
	int lenght=strlen(str);
	long long yz1=0;
	for (long long i=0;i<lenght;++i){
		memset(f,0,sizeof(f));
		for (long long j=i;j<lenght;++j) {
			f[str[j]-'a']++;
			if (yz(i,j))
				yz1++;
		}
	}
	printf("%lld\n",yz1);
	return 0;
}
bool yz(long long start, long long end){
	m=*max_element(f, f + 26);
	return m<=((end-start+1)/2);
}