program Giga_software;
const max = 256;
var fin,fout:text;
    c,nr,i,j,n,m,x,y,q:longint;
    {v:array [1..4096,1..256] of integer;}
    v:array [1..4096,1..max] of word;
    masca:array [0..18] of word;
{*----------------------------------*}

{*----------------------------------*}
begin
    assign(fin,'triplete.in'); reset(fin); assign(fout,'triplete.out'); rewrite(fout);

    masca[1]:=1;
    for i:=2 to 17 do
        masca[i]:=masca[i-1] shl 1;

    readln(fin,n,m);
    for i:=1 to m  do
    begin
        readln(fin,x,y);

        nr:=y div 16 +1;

        v[x,nr]:=v[x,nr] or masca[y mod 16];

        nr:=x div 16 +1;
        v[y,nr]:=v[y,nr] or masca[x mod 16];
    end;

{    for i:=1 to n do
    begin
       for j:=1 to 4 do
       begin
          if v[i,1] and masca[j] = 0 then write(fout,0)
          Else write(fout,1);
       end;
       writeln(fout);
    end;}
{    writeln(fout);}

    for i:=1 to n do
    begin
         nr:=0;
         for j:=1 to max do
         begin
             for q:=1 to 16 do
                  if v[i,j] and masca[q] <> 0 then inc(nr);
         end;
         {writeln(fout,nr);}
         if nr = 3 then inc(c);
    end;

    writeln(fout,c);

    close(fin); Close(fout);
end.