n,l=gets.split.map &:to_i
a=Array.new(l,1)
for i in 2..3200;if a[i]then for j in 2..l/i;a[i*j]=nil end;end;end
s=0
for i in 2..l/(n-1);if a[i]then s+=l-(n-1)*i+1 end;end
puts s