ll@n,@m;
if(n&1){
	ll z=(n-1)*m;
	while(--n&&m){
		ll a=1<<31-__builtin_clz(m);
		m^=a;
		if(n&1){
			z+=2*(a-1&~m);
		}
	}
	wt(z);
}else{
	wt(n*m);
}