A=x2016-100x2015+100x2014-100x2013+...+100x2-100x+100
A = x2016 - (x+1)x2015 + (x+1)x2014 - (x+1)x2013 +....+ (x+1)x2 - (x+1)x + 100
A = x2016 - x2016 - x2015 + x2015 +x2014 - x2014 - x2013 + .......+ x3 + x2 - x2 - x + 100
A = -x + 100
A = -99 + 100
A = 1