var fi,fo:text;
    n,m,k,i:longint;
    a1,a2:array[1..100]of longint;
begin
  assign(fi,'stergeri.in'); reset(fi);
  assign(fo,'stergeri.out'); rewrite(fo);
  read(fi,n,m,k);
  for i:=1 to m do
    read(fi,a1[i],a2[i]);
  for i:=m downto 1 do
    if a1[i]<k then inc(k,a2[i]-a1[i]+1);
  writeln(fo,k);
  close(fi);
  close(fo);
end.