function seg (id, pr, n, a):
  if id == 0:
    inf := 3_000_000_000_000_000_000

    inner := 0
    max_pref := 0
    min_pref := 0
    cur_pref := 0
  
    for i := 0 until n:
      cur_pref += a[i]
      cur_inner := cur_pref - min_pref
      if inner < cur_inner:
        inner := cur_inner

      if min_pref > cur_pref:
        min_pref := cur_pref
      if max_pref < cur_pref:
        max_pref := cur_pref

    print(inner)