#include <stdbool.h>
#include <stdlib.h>

int power(int base, int power) {
    int result = base;
    for (int i = 0; i < power; i++) {
        result *= base;
    }
    return result;
}

bool is_divisible(int num, int divisor) {
    return num % divisor == 0;
}

bool is_even(int num) {
    return is_divisible(num, 2);
}

bool is_odd(int num) {
    return !is_even(num);
}

const char* get_day_name(int weekday) {
    switch(weekday % 7) {
        case 1: return "Sunday";
        case 2: return "Monday";
        case 3: return "Tuesday";
        case 4: return "Wednesday";
        case 5: return "Thursday";
        case 6: return "Friday";
        case 7: return "Saturday";
    }
    return NULL;
}