#include <stdio.h>

int func(int n);

int main(void) {
    printf("main is calling func(42)\n");
    int f = func(42);
    printf("func has returned back to main. func(42) returned %d\n", f);

    return 0;
}

int func(int n) {
    printf("hello from func!\n");
    return 2 * n;
}