{
TASK:platka
LANG:PASCAL
}
program platka;
  var A:array[1..1500,1..1500]of Byte;
      B:array[1..1500,1..1500]of Byte;
      C:array[1..1500]of Boolean;
      m,n,i,j:Integer;
  begin
    for i:=1 to 1500 do
      c[i]:=true;
    for i:= 1 to n do
      for j:= 1 to n do
        a[i,j]:=0;
      readln(n,m);
    for i:=1 to m do
      begin
        readln(i,j);
        a[i,j]:=1;
      end;
    for i:=1 to n do
      for j:=1 to n do
        if a[i,j]=1 then
          c[i]:=false;
    write('Sorry, Pesho ');
    for i:= 1 to 1500 do
      if c[i] then
        write(i,' ');
  end.
