procedure ins(var a:mas; n:integer);
  var i,j,v:integer;
  begin
    for i:=2 to n do begin
      v:=a[i]; j:=i-1;
      while (j>0) and (v<a[j]) do begin
        a[j+1]:=a[j];
        j:=j-1;
      end;
      a[j+1]:=v;
    end;
  end;