Keep Only the Highest Set Bit

#include <stdio.h>
#include <stdint.h>

// Complete the function
uint16_t highest_set_bit(uint16_t reg) {
    uint16_t mask = 0x8000; // set 1 as a highes bit 10000..00
    while ((!(mask & reg)) & (mask != 0))
    {
        mask >>= 1;
    }
    return mask;
}

int main() {
    uint16_t reg;
    scanf("%hu", &reg);

    uint16_t result = highest_set_bit(reg);
    printf("%hu", result);
    return 0;
}