n=gets
a=gets.split.map &:to_i
b=[]
u=[]
a.map{|v|i=b.index{|k|k>=v};j=i ?i: b.size;u+=(-b.size...-j).to_a;b.insert(j,v);}
p u.size
for i in u;puts [-i-1,-i]*' ';end
gets