#include <bits/stdc++.h>

using namespace std;

const int N=100000+10 ;

int last[30];
long long cnt=0;
int main()
{
    string s;
    cin>>s;
    int n=s.length();
    for(int i=1;i<=n;i++){
        int j=s[i-1]-'a';//string s start from 0,it is haxi
        cnt+=1ll *(i-last[j])*(n-i+1);
        last[j]=i;
    }
    cout<<cnt<<endl;
    return 0;
}