what is the difference between the largest and the smallest number written with 7 , 7 , 0 , 7 ?
"7770 7077 - - - - - - - - - - - - - 693 answer : d"
subtract(add(add(add(multiply(multiply(7, const_100), const_10), multiply(7, const_100)), multiply(7, const_10)), 0), add(add(add(const_1000, multiply(7, const_100)), multiply(7, const_10)), 7))