Papeleo escolar
// Your classmates asked you to copy some paperwork for them. You know that there are 'n' classmates and the paperwork has 'm' pages.
// Your task is to calculate how many blank pages do you need. If n < 0 or m < 0 return 0.
/* Example:
n= 5, m=5: 25
n=-5, m=5: 0
*/
const paperwork = (n, m) => (m < 0 || n < 0) ? 0 : m * n
// With love @kouqhar
kouqhar