program stergeri;
var f, g:text;
    n, m, k, i:longint;
    a, b:array[1..100000] of longint;
  begin
    assign(f,'stergeri.in'); reset(f);
    assign(g,'stergeri.out'); rewrite(g);
    readln(f,n,m,k);
    for i:=1 to m do
      read(f,a[i],b[i]);
    for i:=m downto 1 do
      if a[i]<=k then
         k:=k+b[i]-a[i]+1;
    writeln(g,k);
    close(f);
    close(g);
  end.