package main

import (
	"fmt"
	"math/bits"
)

func main() {
	for i := uint64(0); i < 10; i++ {
		fmt.Printf("isPowerOfTwo(%d)=%v\n", i, isPowerOfTwo(i))
	}
}

func isPowerOfTwo(n uint64) bool {
	return bits.OnesCount64(n) <= 1
}