2010-2009+2008-2007…… +2-1 result is odd or even

2010-2009+2008-2007…… +2-1 result is odd or even


Take each minus sign as a group, such as (2010-2009) + (2008-2007) Each group will get 1. There are 1005 groups in 2010 / 2, and 1005 × 1 will get 1005, so it is odd
Hope to adopt