n,l,h,*cc=$<.read.split.map(&:to_i)
l-=1
p (1..n).reduce(0){|r,i|cc.combination(i){|v|e=v.inject(1){|s,x|s*x/s.gcd(x)}
r+=(h/e-l/e)*(i.odd?? i:-i)};r}