#include<stdio.h>
#include<stdlib.h>

struct Pair { 
	int x, y;
};

struct Pair *new_pair() {
	struct Pair *tmp_point = malloc( sizeof( struct Pair ) );
	printf( "Allocating memory at %p\n", tmp_point );

	tmp_point->x = 91;
	tmp_point->y = 42;

	return tmp_point;
}

int main() {
	struct Pair *ptr = new_pair();

	printf( "(%d, %d)\n", ptr->x, ptr->y );

	ptr->y = -42;

	printf( "(%d, %d)\n", ptr->x, ptr->y );

	free( ptr );
	ptr = NULL;

	return 0;
}