#include <stdio.h>
int HA_add(int a, int b)
{
int sum, carry;
while (b != 0)
{
sum = a ^ b;
carry = (a & b) << 1;
a = sum;
b = carry;
}
return sum;
}
int main()
{
printf("%d", HA_add(12, 5));
return 0;
}