#define STOPIT
#include <bits/stdc++.h>
#define loop(n) for (lint ngtkana_is_a_genius = 0; ngtkana_is_a_genius < lint(n); ngtkana_is_a_genius++)
#define rep(i, begin, end) for (lint i = lint(begin); (i) < lint(end); i++)
#define all(v) v.begin(), v.end()
#define rand(l, r) std::uniform_int_distribution<>(l, r)(mt)
using lint = long long;
auto mt = std::mt19937_64(std::random_device{}());
auto cmn = [](auto&& a, auto b){ if (a > b) {a = b; return true;} return false; };
auto cmx = [](auto&& a, auto b){ if (a < b) {a = b; return true;} return false; };
void debug_impl() { std::cerr << std::endl; }
template <typename Head, typename... Tail>
void debug_impl(Head head, Tail... tail) { std::cerr << " " << head; debug_impl(tail...); }
#ifndef STOPIT
#define debug(...)\
  do {\
    std::cerr << std::boolalpha << "[" << #__VA_ARGS__ << "]:";\
    debug_impl(__VA_ARGS__);\
    std::cerr << std::noboolalpha;\
  } while (false)
#else
#define debug(...) {}
#endif

template < typename Container, typename Value = typename Container::value_type, std::enable_if_t<!std::is_same< Container, std::string >::value, std::nullptr_t> = nullptr>
std::istream& operator>> (std::istream& is, Container& v)
  { for (auto & x : v) { is >> x; } return is; }

template < typename Container, typename Value = typename Container::value_type, std::enable_if_t<!std::is_same< Container, std::string >::value, std::nullptr_t> = nullptr >
std::ostream& operator<< (std::ostream& os, Container const& v) {
 os << "{";
  for (auto it = v.begin(); it != v.end(); it++)
    {os << (it != v.begin() ? "," : "") << *it;}
  return os << "}";
}
template <typename T>
auto make_vector_impl(size_t sz, T t) {return std::vector<T>(sz, t);}

template <size_t N, typename T, typename U, std::enable_if_t<N == 1, std::nullptr_t> = nullptr>
auto make_vector(size_t sz, U u) {return make_vector_impl(sz, T(u));}

template <size_t N, typename T, std::enable_if_t<N == 1, std::nullptr_t> = nullptr>
auto make_vector(size_t sz) {return std::vector<T>(sz);}

template <size_t N, typename T, typename... Args, std::enable_if_t<N != 1, std::nullptr_t> = nullptr>
auto make_vector(size_t a, Args... args) {return make_vector_impl(a, make_vector<N - 1, T>(args...));}

template <typename T, typename Size_t>
auto& at(T& t, Size_t i) {return t.at(i);}

template <typename T, typename Size_t, typename... Args>
auto& at(T& t, Size_t i, Args... args) {return at(t.at(i), args...);}

void err() { std::cout << -1 << std::endl; exit(0); }
#define require(exp) do { if (!(exp)) { err(); } } while(false)

template <class Seg, class SegPtr>
struct segment_tree_entry;

template <class Seg, class SegPtr, class Pointer, class Reference>
struct segment_tree_iterator;

template <typename Value, typename BinaryOp>
class segment_tree {
public:
  using value_type = Value;
  using this_type = segment_tree<Value, BinaryOp>;
  using entry_type = segment_tree_entry<this_type, this_type*>;
  using const_entry_type = segment_tree_entry<this_type, this_type const*>;
  using iterator = segment_tree_iterator<this_type, this_type*, value_type*, value_type&>;
  using const_iterator = segment_tree_iterator<this_type, this_type const*, value_type const*, value_type const&>;

friend class segment_tree_entry<this_type, this_type*>;
friend class segment_tree_entry<this_type, this_type const*>;

private:
  int                  sz, n, N;
  BinaryOp             op;
  Value                id;
  std::vector< Value > table;

  auto& op_assign(Value& x, Value y) const
    { return x = op(x, y); }
  void merge(int u)
    { table.at(u) = op(table.at(2 * u), table.at(2 * u + 1)); }

public:
  segment_tree(int sz, BinaryOp op, Value id):
    sz(sz), n(std::pow(2, int(std::log2(2*sz-1)))), N(n * 2), op(op), id(id), table (N, id) {}

  iterator begin()
    { return iterator(this, 0); }

  iterator end()
    { return iterator(this, sz); }

  const_iterator begin() const
    { return const_iterator(this, 0); }

  const_iterator end() const
    { return const_iterator(this, sz); }

  auto at(std::size_t i)
    { return entry_type(this, i); }

  auto at(std::size_t i) const
    { return table.at(n + i); }

  auto& lazy_at(std::size_t i)
    { return table.at(n + i); }

  auto& lazy_at(std::size_t i) const
    { return table.at(n + i); }

  auto collect() const {
    auto ret = std::vector<Value>(sz);
    for (auto i = 0; i < sz; i++)
      { ret.at(i) = at(i); }
    return ret;
  }

  auto query(int l, int r) const {
    auto const dfs = [&](auto&& f, int l, int r, int k, int L, int R) -> Value {
      return l <= L && R <= r ? table.at(k)
        : R <= l || r <= L ? id
        : op(f(f, l, r, 2*k, L, (L+R)/2), f(f, l, r, 2*k+1, (L+R)/2, R));
    };
    return dfs(dfs, l, r, 1, 0, n);
  }

  void build()
    { for (auto i = n - 1; i > 0; i--) merge(i); }
};

template <class Seg, class SegPtr>
class segment_tree_entry {
  using value_type = typename Seg::value_type;
  SegPtr seg;
  std::size_t i;

  auto& get()
    { return seg->table.at(seg->n + i); }

  void build_oneline(int i)
    { for (i += seg->n, i /= 2; i > 0; i /= 2) seg->merge(i); }

public:
  segment_tree_entry(SegPtr seg, std::size_t i) : seg(seg), i(i) {}

  operator value_type() {
    return seg->table.at(seg->n + i);
  }
  void operator=(value_type x) {
    seg->table.at(seg->n + i) = x;
    build_oneline(i);
  }
  void operator+=(value_type x) {
    seg->table.at(seg->n + i) += x;
    build_oneline(i);
  }
  void operator-=(value_type x) {
    seg->table.at(seg->n + i) += x;
    build_oneline(i);
  }
  void operator*=(value_type x) {
    seg->table.at(seg->n + i) += x;
    build_oneline(i);
  }
  void operator/=(value_type x) {
    seg->table.at(seg->n + i) += x;
    build_oneline(i);
  }
};

template <class Seg, class SegPtr, class Pointer, class Reference>
class segment_tree_iterator {
  using this_type = segment_tree_iterator<Seg, SegPtr, Pointer, Reference>;
  using value_type = typename Seg::value_type;
  using pointer = Pointer;
  using reference = Reference;

  template <class Seg_, class SegPtr_, class Pointer_, class Reference_>
  friend bool operator!=(segment_tree_iterator<Seg_, SegPtr_, Pointer_, Reference_>, segment_tree_iterator<Seg_, SegPtr_, Pointer_, Reference_>);

  SegPtr seg;
  std::size_t i;

public:
  segment_tree_iterator(SegPtr seg, std::size_t i) : seg(seg), i(i) {}

  this_type& operator++(){ i++; return *this; }
  this_type  operator++(int){ auto old = *this; ++i; return old; }
  pointer operator->(){ return &seg->at(i); }
  value_type operator*(){ return seg->at(i); }
};

template <class Seg, class SegPtr, class Pointer, class Reference>
bool operator!=(segment_tree_iterator<Seg, SegPtr, Pointer, Reference> a, segment_tree_iterator<Seg, SegPtr, Pointer, Reference> b) {
  return a.i != b.i;
}

template<typename Value, typename BinaryOp>
auto make_segment_tree(int sz, BinaryOp const& op, Value id)
  { return segment_tree<Value, BinaryOp>(sz, op, id); }

int main() {
  std::cin.tie(0); std::cin.sync_with_stdio(false);
  std::string s; std::cin >> s;
  debug(s);
  int n = s.length();

  int alpha = 26;

  std::vector<std::deque<int>> pos(alpha);
  rep(i,0,n) {
    char c = s.at(i);
    pos.at(c-'a').emplace_back(i);
  }
  debug(pos);

  char center = '$';
  std::vector<int> is_former(n);
  rep(i,0,alpha) {
    char c = 'a' + i;
    auto&& v = pos.at(i);
    int sz = v.size();
    if (sz%2==1) {
      require(center=='$');
      center = c;
    }
    rep(i,0,sz/2) {
      is_former.at(v.at(i)) = true;
    }
  }
  assert((n%2==0)==(center=='$'));
  debug(is_former);

  std::string t;
  rep(i,0,n) {
    if (!is_former.at(i)) continue;
    t.push_back(s.at(i));
  }
  t += std::string(t.rbegin(),t.rend());
  if (n%2==1) {
    t.insert(t.begin()+n/2,center);
  }
  debug(t);
  assert((int)t.length()==n);

  lint ans = 0;
  auto seg = make_segment_tree<int>(n,std::plus<>{},0);
  rep(i,0,n) {
    char c = t.at(i);
    auto&& v = pos.at(c-'a');
    assert(!v.empty());
    int j = v.front(); v.pop_front();
    debug(i,j);
    int inv = seg.query(j,n);
    ans += inv;
    seg.at(j) += 1;
  }
  std::cout << ans << std::endl;
  return 0;
}

/*
文字種ごとに、初めの半分が前半に来ます。
奇数は1つまであってよくて、それはあとで付け加えましょう。
場所に前半フラグを立てて、左から順に走査してpush back です。
そして必要なら真ん中を入れて、後半を入れます。
これで文字列は完成したので、今度は文字列ごとにもとの出現箇所を降順（または deque）で保持して、
完成品を走査しながら転倒数を計算です。
*/

Measured memory_bytes: 4628