// example data in .txt file: ABCCAAACACCCCBCBCAACCCCCA

program p;

uses crt;

var filetxt : text;
    Count_C_in_current_chain : integer;
    i : integer;
    S : String;
    max_len_C : integer;
    ch : char;

begin
    assign(filetxt, 'test.txt');
    reset(filetxt);

    max_len_C := 0;
    Count_C_in_current_chain := 0;
    while not eof(filetxt) do
       begin
          read(filetxt, Ch);
          if( ch = 'C') then
             Count_C_in_current_chain := Count_C_in_current_chain + 1
          else
             begin
             if (Count_C_in_current_chain > max_len_C ) then
                begin
                    max_len_C := Count_C_in_current_chain;
                end;
             Count_C_in_current_chain := 0;
             end;
       end;

   write(' Max-length C-chain: ', max_len_C);
   close(filetxt);
end.