CodeForces 576A - Vasya and Petya's Game

#include <iostream>
#include <cstring>
#include <vector>
using namespace std;
int main()
{
int n;
cin>>n;
bool flag[1005];
memset(flag,0,sizeof(flag));
vector<int> v1;
for(int i=2;i<=n;++i)
{
if(flag[i]==0)
{
for(int j=i*i;j<=n;j+=i)
flag[j]=1;
for(int j=i;j<=n;j*=i)
v1.push_back(j);
}
}
cout<<v1.size()<<endl;
int lenth=v1.size();
for(int i=0;i<lenth;++i)
cout<<v1[i]<<" ";
return 0;
}