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

int main()
{
    int a;
    printf("Please give me a number: ");
    scanf ("%i",&a);
    if ( a < 0)
    {
        printf("ERROR. The number is smaller than zero.");
        return 1;
    }
    while ( a >= 1)
    {
        a = a-1;

        printf("%i\n",a);
    }
    //for (a>0 ; a>=0 ; a = a-1)
    //{
        //printf("%i\n",a);
    //}
    return 0;
}