uses crt;
var
t,t2:text;
a:array[1..1000,1..2] of integer;
i,j,n,k:integer;
begin
clrscr;
assign(t,'machanis.dat');
reset(t);
read (t,n);
k:=0;
j:=1;
i:=1;
while not(eof(t)) do begin
read (t,a[i,j]);
k:=k+1;
if j=2  then begin
j:=1; i:=i+1;
end
else
j:=j+1;
end;
close(t);
assign(t2,'machines.res');
rewrite(t2);
if (k mod 4=0) AND  (n mod 2<>0)then
writeln(t2,'yes')
else writeln(t2,'no');
for i:=1 to k div 2 do begin
for j:=1 to 2 do
write(t2,a[i,j],' ');
writeln(t2,' ');
end;
close(t2);
end.