#include using namespace std; // #include // #include // #include // #include #include // #include using namespace atcoder; // #pragma GCC target("avx2") // #pragma GCC optimize("O3") // #pragma GCC optimize("unroll-loops") typedef long long int ll; typedef unsigned long long ull; typedef long double ld; typedef pair pll; typedef vector vll; typedef vector vvll; typedef vector vvvll; typedef vector vpll; typedef vector vvpll; typedef vector vb; typedef vector vvb; typedef vector vd; typedef vector vvd; typedef priority_queue > pqpll; typedef priority_queue > pqll; struct edge{ ll to, cost; edge(ll e_to,ll e_cost): to(e_to), cost(e_cost){} }; typedef vector> Graph; #define rep(i,a,n) for(ll i = a;i < n;i++) #define rrep(i,a,n) for(ll i = n-1; i >= a;i--) #define LINF (1LL << 60) #define INF (1 << 30) #define fs first #define sc second #define EPS (ld)1e-10 #define ALL(a) a.begin(), a.end() #define tcheck(a) if((clock() - start)/(ld)CLOCKS_PER_SEC >= a) break #define debug(s) cout << #s << endl #define debugval(x) cout << #x" = " << x << endl template ll sz(vector &pos){ return (ll)pos.size(); } template ll sz(priority_queue > &que) {return (ll)que.size(); } template ll sz(priority_queue, greater > &que) {return (ll)que.size(); } ll sz(string &s) {return (ll)s.size(); } template void chmin(T &a, T b) { if(a > b) a = b; } template void chmax(T &a, T b) { if(a < b) a = b; } ll gcd(ll a,ll b){ return ((!b) ?a :gcd(b, a%b)); } ll lcm(ll a,ll b){ return a / gcd(a,b) * b; } // ll dx[4] = {0,-1,0,1},dy[4] = {-1,0,1,0}; ll dx[8] = {0,-1,-1,-1,0,1,1,1},dy[8] = {-1,-1,0,1,1,1,0,-1}; inline bool isinside(ll i,ll n){ return (i < n && i >= 0); } int main(){ string s; cin >> s; ll ans = 0; vll cnt(26); rep(i,0,sz(s)){ cnt[s[i] - 'A']++; //s[i]が3文字目になる部分列の数 rep(j,0,26){ if('A' + j == s[i]) continue; ans += cnt[j]*(cnt[j]-1)/2; } } cout << ans << endl; }