#include <stdio.h>

void add_one(int v) {
    printf("initial value of v from add_one() = %d\n", v);
    v = v + 1;
    printf("final value of v from add_one() = %d\n", v);
}

int main() {
    int x = 10;
    printf("initial value of x from main() = %d\n", x);

    add_one(x);
    printf("final value of x from main() = %d\n", x);
    
    return 0;
}