Codeforces864B-Polycarp and Letters

Polycarp and Letters

Polycarp loves lowercase letters and dislikes uppercase ones. Once he got a string sconsisting only of lowercase and uppercase Latin letters.

Let A be a set of positions in the string. Let's call it pretty

• letters on positions from A
• there are no uppercase letters in the string which are situated between positions from A (i.e. there is no such j that s[j] is an uppercase letter, anda₁ < j < a₂ for some a₁ and a₂ from A).

Write a program that will determine the maximum number of elements in a pretty

Input

The first line contains a single integer n (1 ≤ n ≤ 200) — length of string s.

The second line contains a string s

Output

Print maximum number of elements in pretty set of positions for string s.

Example

Input

11 aaaaBaabAbA

Output

2

Input

12 zACaAbbaazzC

Output

3

Input

3 ABC

Output

0

Note

In the first example the desired positions might be 6 and 8 or 7 and 8. Positions 6and 7 contain letters 'a', position 8 contains letter 'b'. The pair of positions 1and 8 is not suitable because there is an uppercase letter 'B' between these position.

In the second example desired positions can be 7, 8 and 11. There are other ways to choose pretty

In the third example the given string s does not contain any lowercase letters, so the answer is 0.

题意：给出一个字符串，由一个个大写字母分隔成多个区域。求各个区域中最多的不同的字母个数的数量。依然模拟求解。

Code：

var
  l,i,ans,k:longint;ch:char;
  a:array['a'..'z'] of longint;
begin
  readln(l);
  for i:=1 to l do
  begin
    read(ch);
    if (ch>='a')and(ch<='z') then
    begin
      inc(a[ch]);
      if a[ch]=1 then inc(k);
    end else
    begin
      if k>ans then ans:=k;
      k:=0;
      fillchar(a,sizeof(a),0);
    end;
  end;
  if k>ans then ans:=k;
  writeln(ans);
end.