#include<stdio.h>
#define N 6
#define MAXN 100000001
int main(){
int lamp[MAXN],i,j,answer;
for(i=1;i<=N;i++)lamp[i]=0;
for(i=1;i<=N;i++)for(j=i;j<=N;j+=i){
if(lamp[j]==0)lamp[j]=1;
else lamp[j]=0;
}
answer=0;
for(i=1;i<=N;i++)if(lamp[i]==1)answer++;
printf("%d\n",answer);
return 0;
}