{$apptype console}
const
  len=3215;
var
  words:array[1..4,1..len] of integer;
procedure loadwords;
var
  f:text;
  i:Integer;
  j:integer;
  s:string;
  c:char;
begin
  for i:=1 to 4 do
  begin
    str(i,s);
    s:='basicword'+s+'.txt';
    assign(f,s);
    reset(f);
    for j:=1 to len do
    begin
      read(f,c);
      words[i,j]:=ord(c)-ord('a');
    end;
    close(f);
  end;
end;
var
  sum:array[1..3*len] of integer;
procedure outno1;
begin
  writeln('check1: no');
  readln;
end;
procedure outno2;
begin
  writeln('check2: no');
  readln;
end;
procedure outno3;
begin
  writeln('check3: no');
  readln;
end;
procedure check1;
var
  i,j:integer;
  s1,s2:integer;
begin
  for s1:=1 to 4 do
    for s2:=1 to 4 do
    if s1<>s2 then
    begin
      for i:=1 to len do
        sum[i]:=words[s1,i];
      for i:=1 to len do
        sum[i+len]:=words[s2,i];
    end;
  for i:=1 to len-2 do
  begin
    for s1:=1 to 4 do
    begin
      j:=1;
      while j<=len do
      begin
        if sum[i+j]<>words[s1,j] then break;
        inc(j);
      end;
      if j>len then outno1;
    end;
  end;
  writeln('check1: ok');
end;
procedure check2;
var
  i,j,k,l:integer;
  s1,s2,s3:integer;
begin
  for s1:=1 to 4 do
    for s2:=1 to 4 do
    if (s1<>s2) and odd(s2-s1) then
    begin
      for s3:=1 to 4 do
      if (s2<>s3) and odd(s2-s3) then
      begin
        for i:=1 to len do
          sum[i]:=words[s1,i];
        for i:=1 to len do
          sum[i+len]:=words[s2,i];
        for i:=1 to len do
          sum[i+2*len]:=words[s3,i];
        for j:=1 to 3*len-1 do
          for k:=1 to ((3*len-j+1) div 2) do
          begin
            l:=1;
            while l<=k do
            begin
              if sum[j+l-1]<>sum[j+l+k-1] then break;
              inc(l);
            end;
            if l>k then outno2;
          end;
      end;
    end;
  writeln('check2: ok');
end;
procedure check3;
var
  s1,s2,s3,s4:integer;
  i,j:integer;
begin
  for s1:=1 to 4 do
    for s2:=1 to 4 do
      for s3:=1 to 4 do
      if (s1<>s2) and (s2<>s3) then
      begin
        for i:=1 to len do
          sum[i]:=words[s1,i];
        for i:=1 to len do
          sum[i+len]:=words[s2,i];
        for i:=1 to len do
          sum[i+2*len]:=words[s3,i];
        for i:=2 to len do
        begin
          j:=1;
          while j<=len do
          begin
            if sum[i+j-1]<>sum[i+j+len-1] then
              break;
            inc(j);
          end;
          if j>len then outno3;
        end;
      end;
  writeln('check3: ok');
end;
begin
  loadwords;
  check1;
  check2;
  check3;
  readln;
end.