def gcd(a,b);0<b ?gcd(b,a%b): a;end
n,l,h,*cc=(gets+gets).split.map(&:to_i)
l-=1
r=cc.reduce(0){|s,c|s+h/c-l/c}
2.upto(n){|i|cc.combination(i){|v|e=v.inject(1){|s,x| s*x/gcd(s,x)}
r+=(h/e-l/e)*(i.odd?? i:-i)}}
p r