type del=record
   x,y:longint;
   end;
var a:array[1..10000]  of del;
i,n,m,k:longint;
f,g:text;
begin
assign(f,'stergeri.in');
assign(g,'stergeri.out');
reset(f);
rewrite(g);
read(f,n,m,k);
for i:=1 to m do
   read(f,a[i].x,a[i].y);
for i:=m downto 1 do
   if a[i].x<=k then
      k:=k+(a[i].y-a[i].x+1);
writeln(g,k);
close(f);
close(g);
end.