[C]: printf / scanf functions are evil

I'm just starting to learn C and the first exercise made in class was to make a program that prints the sum of two integers.

This program:

#include <stdio.h>
#include <stdlib.h>
int main (void) {
  int n1,n2;
  printf("1st int: ");
  scanf("%d",&n1);
  printf("2nd int: ");
  scanf("%d",&n2);
  printf("Sum = %d\n",n1+n2);
  return EXIT_SUCCESS;
}

I showed it to some of my older classmates and went batshit insane with it saying: DO NOT USE PRINTF AND SCANF, THEY ARE NOT FUCKING SAME and other stuff.

Will someone please input on this matter?
Thank you!

;; >>59
;; Sure thing bro
(defun prompt (prompt)
  (princ prompt *query-io*)
  (read *query-io*))
(format t "Sum = ~a"
        (+ (prompt "1st int: ")
           (prompt "2nd int: ")))