



def      __lowercase       (			a__       )    ->			int:
							if not head:
														return True
							# split the list to two parts
							__SCREAMING_SNAKE_CASE							,	__SCREAMING_SNAKE_CASE									= head.next, head
							while fast and fast.next:
														__SCREAMING_SNAKE_CASE									= fast.next.next
														__SCREAMING_SNAKE_CASE									= slow.next
							__SCREAMING_SNAKE_CASE									= slow.next
							__SCREAMING_SNAKE_CASE									= None  # Don't forget here! But forget still works!
							# reverse the second part
							__SCREAMING_SNAKE_CASE									= None
							while second:
														__SCREAMING_SNAKE_CASE									= second.next
														__SCREAMING_SNAKE_CASE									= node
														__SCREAMING_SNAKE_CASE									= second
														__SCREAMING_SNAKE_CASE									= nxt
							# compare two parts
							# second part has the same or one less node
							while node:
														if node.val != head.val:
																					return False
														__SCREAMING_SNAKE_CASE									= node.next
														__SCREAMING_SNAKE_CASE									= head.next
							return True






def      __lowercase       (			a__       )    ->			List[str]:
							if not head or not head.next:
														return True

							# 1. Get the midpoint (slow)
							__SCREAMING_SNAKE_CASE									= __SCREAMING_SNAKE_CASE									= __SCREAMING_SNAKE_CASE									= head
							while fast and fast.next:
														__SCREAMING_SNAKE_CASE							,	__SCREAMING_SNAKE_CASE									= fast.next.next, slow.next

							# 2. Push the second half into the stack
							__SCREAMING_SNAKE_CASE									= [slow.val]
							while slow.next:
														__SCREAMING_SNAKE_CASE									= slow.next
														stack.append(slow.val       )

							# 3. Comparison
							while stack:
														if stack.pop() != cur.val:
																					return False
														__SCREAMING_SNAKE_CASE									= cur.next

							return True






def      __lowercase       (			a__       )    ->			List[str]:
							if not head or not head.next:
														return True
							__SCREAMING_SNAKE_CASE									= {}
							__SCREAMING_SNAKE_CASE									= 0
							while head:
														if head.val in d:
																					d[head.val].append(a__       )
														else:
																					__SCREAMING_SNAKE_CASE									= [pos]
														__SCREAMING_SNAKE_CASE									= head.next
														pos += 1
							__SCREAMING_SNAKE_CASE									= pos - 1
							__SCREAMING_SNAKE_CASE									= 0
							for v in d.values():
														if len(a__       ) % 2 != 0:
																					middle += 1
														else:
																					__SCREAMING_SNAKE_CASE									= 0
																					for i in range(0							,       len(a__       )       ):
																												if v[i] + v[len(a__       ) - 1 - step] != checksum:
																																			return False
																												step += 1
														if middle > 1:
																					return False
							return True











import os






def      __lowercase       (			a__ = "input.txt"       )    ->			int:

							with open(os.path.join(os.path.dirname(a__       )							,       a__       )       ) as input_file:
														__SCREAMING_SNAKE_CASE									= [
														    [int(a__       ) for element in line.split(','       )]
														    for line in input_file.readlines()
														]

							__SCREAMING_SNAKE_CASE									= len(a__       )
							__SCREAMING_SNAKE_CASE									= len(matrix[0]       )

							__SCREAMING_SNAKE_CASE									= [[-1 for _ in range(a__       )] for _ in range(a__       )]
							for i in range(a__       ):
														__SCREAMING_SNAKE_CASE									= matrix[i][0]

							for j in range(1							,       a__       ):
														for i in range(a__       ):
																					__SCREAMING_SNAKE_CASE									= minimal_path_sums[i][j - 1] + matrix[i][j]

														for i in range(1							,       a__       ):
																					__SCREAMING_SNAKE_CASE									= min(
																					    minimal_path_sums[i][j]							,       minimal_path_sums[i - 1][j] + matrix[i][j]       )

														for i in range(rows - 2							,       -1							,       -1       ):
																					__SCREAMING_SNAKE_CASE									= min(
																					    minimal_path_sums[i][j]							,       minimal_path_sums[i + 1][j] + matrix[i][j]       )

							return min(minimal_path_sums_row[-1] for minimal_path_sums_row in minimal_path_sums       )


if __name__ == "__main__":
			print(F'''{solution() = }''')






