var n,m,k,x,y,i,l:longint;
    f,g:text;
begin
assign(f,'stergeri.in');
assign(g,'stergeri.out');
reset(f);
rewrite(g);
readln(f,n,m,k);
for i:=1 to m do begin
                 readln(f,x,y);
                 l:=l+y-x+1;
                 if x<k then begin
                             k:=k+l;
                             l:=0;
                             end;
                 end;
write(g,k);
close(f);
close(g);
end.