Write a function named upc in C that determine Universal Product code is valid or not. The function accepts a char and returns an int. The function returns 1 if the UPC is valid and it must return 2 if the number is invalid. For example, for the char '036000241457' it should return 1.

Please use the function below as template

int upc(char *upc){

}

Please show all your work and thought process And please write it in C