#include <stdio.h>

#if 0
void print_hello() {
    printf("Hello, world!\n");
}

void call_function(void (*function)()) {
    (*function)();
}

int main() {
    call_function(&print_hello);
    return 0;
}
#endif

int callback(int num) {
    printf("value reached to the end %d\n", num);
    return 0;
}

int str(int num, int (fn)()){
    (fn)();
    printf("Hi Hello\n");
    return 0;
}

int main(){
    int var = 5;
    
    str(5, callback);
    return 0;
}