function pangrams(s) {
    return isPangram(s.toLowerCase()) ? "pangram" : "not pangram"
}
const pangramRegex = /^(?=.*a)(?=.*b)(?=.*c)(?=.*d)(?=.*e)(?=.*f)(?=.*g)(?=.*h)(?=.*i)(?=.*j)(?=.*k)(?=.*l)(?=.*m)(?=.*n)(?=.*o)(?=.*p)(?=.*q)(?=.*r)(?=.*s)(?=.*t)(?=.*u)(?=.*v)(?=.*w)(?=.*x)(?=.*y)(?=.*z).*$/

const isPangram = (str) => pangramRegex.test(str);