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

extern void dupa2(void);

void dupa(void) {
    printf("a\n");
    printf("b\n");
    printf("c\n");
}

int main(void)
{
    printf("main at 0x%"PRIxPTR"\n", (uintptr_t)&main);

    for (int i = 1; i <= 20; i++) {
        printf("i = %d\n", i);
        if (i % 10 == 0) {
            dupa();
        }
    }

    dupa2();

    int *a = NULL;
    *a = 6969;

    return 0;
}