#include <stdbool.h>

int bitSquareSum(int n)
{
    int sum = 0;
    while (n > 0)
    {
        int bit = n % 10;
        sum += bit * bit;
        n /= 10;
    }

    return sum;
}

bool isHappy(int n)
{
    int slow = n, fast = n;
    do
    {
        slow = bitSquareSum(slow);
        fast = bitSquareSum(fast);
        fast = bitSquareSum(fast);
    } while (slow != fast);

    return slow == 1;
}

int main()
{
    return 0;
}