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

int main()
{
    int *x;
    x=(int *)malloc(sizeof(int));
    *x=10;
    printf("%d \n",x);
    printf("%d \n",*x);
    scanf("%d",x);
    printf("%d \n",x);
    printf("%d \n",*x);
    printf("Hello world!\n");
    return 0;
}