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

char*mmap();
#define rd(v) int v=0;{int _c;while(_c=*rp++-48,_c>=0)v=v*10+_c;}

#define wt_rev(v) {long _z=v;do*--wp=_z%10+48;while(_z/=10);}

unsigned long vis[50000000/64+4];

main(){
	char*rp=mmap(0l,1l<<25,1,2,0,0ll);
	rd(n);
	long res=0;

	long n9=n/9+1;
	for(long i=1;i<n9;++i){
		if(!(vis[i>>6]&1ul<<i)){
			long count=1;
			for(int j=2,ijj;ijj=i*j*j,ijj<=n;++j){
				vis[ijj>>6]|=1ul<<ijj;
				count+=1;
			}
			res+=count*count;
		}
	}

	long n4=n/4+1;
	for(long i=n9;i<n4;++i){
		if(!(vis[i>>6]&1ul<<i)){
			int ijj=i*4;
			vis[ijj>>6]|=1ul<<ijj;
			res+=4;
		}
	}

	if(n4&63){
		vis[n4>>6]|=~0ul>>-n4;
	}
	vis[n+1>>6]|=~0ul<<n+1;

	long e=(n>>6)+1;
	res+=e-(n4>>6)<<6;
	for(long i=n4>>6;i<e;++i){
		res-=__builtin_popcountl(vis[i]);
	}

	char wbuf[64],*wp=wbuf+sizeof wbuf;
	wt_rev(res);
	write(1,wp,wbuf+sizeof wbuf-wp);
	_exit(0);
}