var
	n,s,i,t,min,tem,q:longint;
	boo:boolean;
	a,b:array[0..1000010] of longint;
 
begin
	readln(n,s);
	while n<>0 do
	begin
		boo:=true;
		readln(s);
		for i:=1 to n do
		readln(a[i],b[i]);
		t:=n;
		while (t>0)and(boo=true) do
		begin
			min:=1000000000;
			for i:=1 to t do
			if b[i]<min then
			begin
				min:=b[i];
				q:=i;
			end;
			tem:=b[q];
			b[q]:=b[t-1];
			b[t-1]:=tem;
			tem:=a[q];
			a[q]:=a[t-1];
			a[t-1]:=tem;
			if (s<b[t-1]) then begin writeln('NO'); boo:=false; end
			else s:=s+a[t-1];
			t:=t-1;
		end;
		if t=0 then writeln('YES');
		read(n);
	end;
end.

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

NCAwCjEgMAoyIDIKMSAxCjIgMgowIDA=

4 0
1 0
2 2
1 1
2 2
0 0