#include <stdio.h>

int f(int n);

int main(void) {
    printf("calling function f\n");
    int result = f(22);
    printf("back from function f\n");
    printf("%d", result);
    putchar('\n');
    return 0;
}

int f(int x) {
    printf("in function f\n");
    printf("%d", x);
    putchar('\n');
    return 2 * x;
}