var
  n,m,x,i,j,y,ans:longint;
  l,r,w:array[0..1000000]of longint;

begin
  assign(input,'max.in'); reset(input);
  assign(output,'max.out'); rewrite(output);
  readln(n,m);
  for i:=1 to n do readln(l[i],r[i],w[i]);
  for i:=1 to m do
  begin
    readln(x,y);
    ans:=0;
    for j:=1 to n do
    if (l[j]>=x)and(r[j]<=y)and(w[j]>ans) then ans:=w[j];
    writeln(ans);
  end;
  close(input);
  close(output);
end.