void setup() {
    // Initialize serial communication at 9600 bits per second:
    Serial.begin(9600);
    
    int a = 10;
    int b = 20;

    // Print original values
    Serial.print("Original a: ");
    Serial.println(a);
    Serial.print("Original b: ");
    Serial.println(b);

    // Swap values using pointers
    swap(&a, &b);

    // Print swapped values
    Serial.print("Swapped a: ");
    Serial.println(a);
    Serial.print("Swapped b: ");
    Serial.println(b);
}

void loop() {
    // Nothing to do here
}

void swap(int *ptr1, int *ptr2) {
    int temp = *ptr1;
    *ptr1 = *ptr2;
    *ptr2 = temp;
}