text: # Solution of;
  # Project Euler Problem 507: Shortest Lattice Vector
  # https://projecteuler.net/problem=507
  # 
  # Let $t_n$ be the tribonacci numbers defined as:$t_0 = t_1 = 0$;$t_2 = 
  # 1$;$t_n = t_{n-1} + t_{n-2} + t_{n-3}$ for $n \ge 3$and let $r_n = t_n 
  # \text{ mod } 10^7$. For each pair of Vectors $V_n=(v_1,v_2,v_3)$ and 
  # $W_n=(w_1,w_2,w_3)$ with $v_1=r_{12n-11}-r_{12n-10}, 
  # v_2=r_{12n-9}+r_{12n-8}, v_3=r_{12n-7} \cdot r_{12n-6}$ and 
  # $w_1=r_{12n-5}-r_{12n-4}, w_2=r_{12n-3}+r_{12n-2}, w_3=r_{12n-1} \cdot 
  # r_{12n}$we define $S(n)$ as the minimal value of the manhattan length of the 
  # vector $D=k \cdot V_n+l \cdot W_n$ measured as $|k \cdot v_1+l \cdot w_1|+|k 
  # \cdot v_2+l \cdot w_2|+|k \cdot v_3+l \cdot w_3|$ for any integers $k$ and 
  # $l$ with $(k,l)\neq (0,0)$. The first vector pair is (-1, 3, 28), (-11, 125, 
  # 40826). You are given that $S(1)=32$ and $\sum_{n=1}^{10} 
  # S(n)=130762273722$. Find $\sum_{n=1}^{20000000} S(n)$.
  # 
  # by lcsm29 http://github.com/lcsm29/project-euler
  import timed
  
  
  def dummy(n):
      pass
  
  
  if __name__ == '__main__':
      n = 1000
      i = 10000
      prob_id = 507
      timed.caller(dummy, n, i, prob_id)
  