#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

#define rd_skip() while(*rp++>=48)
#define rd() ({long _v=0,_c;while(_c=*rp++-48,_c>=0)_v=_v*10+_c;_v;})
#define wt(v) {ulong _z=v;do*--wp=_z%10+48;while(_z/=10);}
#define rep4(v,s,e,t) for(long v=s;v<e;v+=t)
#define rrep3(v,s,e) for(long v=e;--v>=s;)

typedef unsigned long ulong;

char a[200004];

ulong f1(){
	char*mmap();
	char*rp=mmap(0l,1l<<25,1,2,0,0ll);
	ulong n=rd();
	rd_skip();
	while(*rp){
		a[rd()]=1;
	}
	return n;
}

ulong f2(ulong n){
	ulong z=n;
	rrep3(i,1,n+1){
		ulong x=0;
		rep4(j,i,n+1,i){
			x^=a[j];
		}
		z-=x;
		a[i]=x;
	}
	return z;
}

void f3(ulong z){
	char wbuf[64],*wp=wbuf+sizeof wbuf;
	wt(z);
	write(1,wp,wbuf+sizeof wbuf-wp);
}

int main(){
	f3(f2(f1()));
	_exit(0);
}