var n,k:longint;
    i,m:0..100000;
    st,fn:array[0..100000]of longint;
    t:text;
begin
 assign(t,'stergeri.in'); reset(t);
  readln(t,n,m,k);
  for i:=m downto 1 do readln(t,st[i],fn[i]);
 close(t);
 for i:=1 to m do
  if k>=st[i] then k:=k+(fn[i]-st[i]+1);
 assign(t,'stergeri.out'); rewrite(t);
  writeln(t,k);
 close(t);
end.