function [e_val,e_vec]=invpower_n(A,v0,e)
  v0=v0/norm(v0,inf)
  v=inv(A)*v0
  l=1/norm(v,inf)
  v=v/norm(v,inf)
  for i=1:n-1
    v0=v
    v=inv(A)*v0
    l=1/norm(v,inf)
    v=v/norm(v,inf)
  end
  e_val=l*sign(v(1)/v0(1))
  e_vec=v
endfunction