var aux,aux2,g,w,i,j,s:integer;
eg,cg:array[1..10001] of integer;
fin,fout:text;
begin
assign(fin,'energii.in');
assign(fout,'energii.out');
reset(fin);
rewrite(fout);
readln(fin,g);
readln(fin,w);
for i:=1 to g do readln(fin,eg[i],cg[i]);
for i:=1 to g-1 do
for j:=i+1 to g do
if eg[i]<eg[j] then begin
aux:=eg[i];
aux2:=cg[i];
eg[i]:=eg[j];
cg[i]:=cg[j];
eg[j]:=aux;
cg[j]:=aux2;
end;
for i:=1 to g do
if eg[i]=w then writeln(fout,cg[i]);
close(fin);
close(fout);
end.