#include <bits/stdc++.h>
#define ll long long
#define mp make_pair
#define fi first
#define se second
#define pb push_back
#define vi vector<int>
#define pi pair<int, int>
#define maxn 200005
#define mod 998244353
template<typename T> bool chkmin(T &a, T b){return (b < a) ? a = b, 1 : 0;}
template<typename T> bool chkmax(T &a, T b){return (b > a) ? a = b, 1 : 0;}
ll ksm(ll a, ll b) {if (b == 0) return 1; ll ns = ksm(a, b >> 1); ns = ns * ns % mod; if (b & 1) ns = ns * a % mod; return ns;}
using namespace std;
#define bs bitset<maxn> 
bs suf[26], tr[26];
bs cans;
char s[maxn];
int main() {
    scanf("%s", s + 1);
    int n = strlen(s + 1);
    ll ans = 0;
    for (int i = n; i >= 1; i--) {
        cans = (cans << 1) & tr[s[i] - 'a'];
        cans |= suf[s[i] - 'a'];
        tr[s[i] - 'a'][i] = 1;
        for (int j = s[i] - 'a' + 1; j < 26; j++)
            suf[j][i] = 1;
        ans += cans.count();
    }
    cout << ans << endl;
    
    return 0;
}
/*
5 5 1 2
1 2 2
5 5 1 2
1 2 2
2 3 2
3 4 3
4 5 1
2 5 2
2 3 2
3 4 3
4 5 1
2 5 2
*/