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#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 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;
int n;
const int maxn = 500005;
char inp[maxn];
map<pi, int> h, g[3], u[3];
int s[3];
int main() {    
    scanf("%s", inp + 1);
    int n = strlen(inp + 1);
    ll ans = 0;
    for (int i = 0; i <= n; i++) {
        if (i) s[inp[i] - 'a'] += 1;
        for (int i = 0; i < 3; i++) {
            int f = s[(i + 1) % 3], m = s[(i + 2) % 3];
            pi ca = mp(f - m, s[i]);
            ans += g[i][ca], g[i][ca] += 1;
            ca = mp(f, m);
            ans += u[i][ca], u[i][ca] += 1;
        }
        pi cur = mp(s[0] - s[1], s[0] - s[2]);
        ans += h[cur], h[cur] += 1;
    }
    cout << ans << endl;
    return (0-0); // <3 cxr
}