function solution(n){
let number= [];
for(let i = 0; i<=n ; i++){
number.push(i)
}
for(let i = 2;i<=n; i++){
for(let j = i+i ; j<number.length; j+=i){
number[j] = 0;
}
}
number.shift();
number.shift();
return number.filter(item=>item!==0).length;
}
const n = 40;
console.log(solution(n))