p:array [1..30000] of longint;

i,j,w,n,b,c:longint;

s:qword;

begin

readln(w);

readln(n);

for i:=1 to n do

readln(p[i]);

for i:=n downto 1 do

for j:=1 to i-1 do

if p[j]>p[j+1] then

begin

c:=p[j];

p[j]:=p[j+1];

p[j+1]:=c;

end;

s:=0;

i:=1;

j:=n;

while n>1 do

if (p[i]+p[j])<=w then

begin

s:=s+1;

n:=n-2;

i:=i+1;

j:=j-1;

end

else

begin

s:=s+1;

n:=n-1;

j:=j-1;

end;

if n=1 then s:=s+1;

writeln(s);

end.

错哪里了？