Var
 X1,X2,X3,Y,Y1:Set of Byte;
 i,P:Byte;
Begin
 X1:=[];
 X2:=[];
 X3:=[];
 for i:= 1 to 20 do X1:=X1+[i];
 for i:=10 to 30 do X2:=X2+[i];
 for i:=11 to 21 do X3:=X3+[i];
 Y:=(X1+X2)*(X1+X3)-(X2+X3);
 Write(' Y: ');
 for i:=1 to 30 do
  if i in Y then write(i:3);
 Writeln;
 Write('Y1: ');
 Y1:=[];
 P:=0;
 for i:=1 to 30 do
  if (i in Y) and ((i mod 4)=0) and not (i in Y1) then
   begin
    Y1:=Y1+[i];
    write(i:3);
    Inc(P);
   end;
 Writeln;
 Writeln('P(Y1) = ',P);
 Readln
End.

Var
 S1,S2:String;
 i,k1,k2:byte;
 b:boolean;
Begin
 Repeat
  b:=false;
  writeln('Enter the string:');
  Readln(S1);
  for i:=1 to Length(S1) do
   if S1[i]='*' then b:=true;
 Until b;
 Writeln;
 Writeln;
 Writeln;
 k1:=0;
 Repeat
  Inc(k1);
 Until S1[k1]='*';
 k2:=Length(S1)+1;
 Repeat
  Dec(k2);
 Until S1[k2]='*';
 S2:='';
 for i:=k1 to k2 do
  S2:=S2+S1[i];
 k1:=k1-1;
 k2:=Length(S1)-k2;
 Writeln('Initial string:');
 Writeln(S1);
 Writeln('Length = ',Length(S1));
 Writeln;
 Writeln('New string:');
 Writeln(S2);
 Writeln('Length = ',Length(S2));
 Writeln;
 Writeln('Number of excluded symbols = ',k1+k2);
 Readln
End.