Problem: You are given a string s consisting only of first 20 lowercase Latin letters ('a', 'b', ..., 't').

Recall that the substring s[l; r] of the string s is the string s_l s_{l + 1} ... s_r. For example, the substrings of "codeforces" are "code", "force", "f", "for", but not "coder" and "top".

You can perform the following operation no more than once: choose some substring s[l; r] and reverse it (i.e. the string s_l s_{l + 1} ... s_r becomes s_r s_{r - 1} ... s_l).

Your goal is to maximize the length of the maximum substring of s consisting of distinct (i.e. unique) characters.

The string consists of distinct characters if no character in this string appears more than once. For example, strings "abcde", "arctg" and "minecraft" consist of distinct characters but strings "codeforces", "abacaba" do not consist of distinct characters.

Input

The only line of the input contains one string s consisting of no more than 10^6 characters 'a', 'b', ..., 't' (first 20 lowercase Latin letters).

Output

Print one integer — the maximum possible length of the maximum substring of s consisting of distinct characters after reversing no more than one its substring.

Examples

Input


abacaba


Output


3


Input


abcdecdf


Output


6


Input


aabbcc


Output


3


Input


abcdeefc


Output


6

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
int setbit(int n, int pos) { return n = n | (1 << pos); }
int resetbit(int n, int pos) { return n = n & ~(1 << pos); }
bool checkbit(int n, int pos) { return (bool)(n & (1 << pos)); }
template <typename T>
T modMul(T x, T y, T mod = 1e9 + 7) {
  x %= mod;
  y %= mod;
  return (x * y) % mod;
}
template <typename T>
T modAdd(T x, T y, T mod = 1e9 + 7) {
  x %= mod;
  y %= mod;
  return (x + y) % mod;
}
template <typename T>
T ext_gcd(T num1, T num2, T &X, T &Y) {
  T r2, r1, q2, q1, x2, x1, y2, y1, x, y, r;
  x2 = 1;
  y2 = 0;
  x1 = 0;
  y1 = 1;
  for (r2 = num1, r1 = num2; r1 != 0;
       y2 = y1, y1 = y, x2 = x1, x1 = x, r2 = r1, r1 = r) {
    q1 = r2 / r1;
    x = x2 - q1 * x1;
    y = y2 - q1 * y1;
    r = r2 % r1;
  }
  X = x2;
  Y = y2;
  return r2;
}
template <typename T>
void print(const T &v) {
  cerr << v << ' ';
}
template <typename T1, typename... T2>
void print(const T1 &first, const T2 &...rest) {
  print(first);
  print(rest...);
}
template <class T>
string to_str(T t) {
  stringstream second;
  second << t;
  return second.str();
}
template <typename T>
T modPow(T x, T k, T mod = 1e9 + 7) {
  if (k == 0) return (T)1;
  if (k & 1) {
    return ((x % mod) * modPow(x, k - 1, mod) % mod) % mod;
  } else {
    T ret = modPow(x, k / 2, mod);
    ret %= mod;
    return (ret * ret) % mod;
  }
}
template <typename T>
T modInv(T x, T m) {
  return modPow(x, m - 2, m);
}
template <typename T>
void dbg_a(T a[], int n = 10) {
  cerr << "[ ";
  for (int i = 0; i < n; i++) cerr << a[i] << ' ';
  cerr << " ]"
       << "\n";
}
template <typename F, typename S>
ostream &operator<<(ostream &os, const pair<F, S> &p) {
  return os << "[ " << p.first << ", " << p.second << " ]";
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "[ ";
  for (int i = 0; i < v.size(); i++) os << v[i] << ' ';
  return os << " ]\n";
}
template <typename T>
ostream &operator<<(ostream &os, const map<T, T> &Map) {
  os << "[ ";
  for (__typeof((Map).begin()) it = (Map).begin(); it != (Map).end(); ++it)
    os << "[" << (*it).first << ' ' << (*it).second << "] ";
  return os << "]\n";
}
template <typename T>
ostream &operator<<(ostream &os, const set<T> &Set) {
  os << "[ ";
  for (__typeof((Set).begin()) it = (Set).begin(); it != (Set).end(); ++it)
    os << *it << ' ';
  return os << " ]\n";
}
const int maxn = (int)2e6 + 123;
const int inf = 0x3f;
const long long mod = (long long)1e9 + 7LL;
int dp[21][(1 << 20) + 123], n;
int Mask, len, cnt[(1 << 21) + 123], a[maxn + 2];
int F[(1 << 21) + 123];
int count_bit(int x) {
  int cntb = 0;
  for (int i = 0; i < 20; i++) cntb += checkbit(x, i);
  return cntb;
}
void solve() {
  int x;
  string s;
  cin >> s;
  for (int i = 0; i < s.size(); i++) {
    int mask = 0;
    for (int j = i; j >= 0; j--) {
      int id = s[j] - 'a';
      if (checkbit(mask, id) == 1) break;
      mask = setbit(mask, id);
      cnt[mask] = count_bit(mask);
    }
    a[i] = mask;
  }
  for (int mask = 0; mask < (1 << 20); mask++) {
    dp[0][mask] = cnt[mask];
    if (mask & 1) {
      dp[0][mask] = max(dp[0][mask], cnt[mask ^ 1]);
    }
    for (int i = 1; i <= 20; i++) {
      dp[i][mask] = max(dp[i][mask], dp[i - 1][mask]);
      if (checkbit(mask, i) == 1) {
        dp[i][mask] = max(dp[i][mask], dp[i - 1][mask ^ (1 << i)]);
      }
    }
    F[mask] = dp[19][mask];
  }
  int ans = 0;
  Mask = (1 << 20) - 1;
  for (int i = 0; i < s.size(); i++) {
    int rev = a[i] ^ Mask;
    ans = max(ans, F[rev] + cnt[a[i]]);
  }
  cout << ans << "\n";
}
int main() {
  ios ::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int t = 1, c = 0;
  while (t--) {
    solve();
  }
  return 0;
}