RSH1

#include <iostream>
#include <vector>
using namespace std;

int gcd(int a,int b)
{
    if(a<b)
        return gcd(b,a);
    if(a%b==0)
        return b;
    else return gcd(b,a%b);
}

int phi(int x)
{
    int ans=0;
    for(int i=1;i<=x;++i)
    {
        if(gcd(x,i)==1)
            ans++;
    }
    return ans;
}

int main()
{
    int ans=0;
    for(int i=1;i<1e4;++i)
        ans+=(phi(i)>=phi(2*i+1));
    cout<<ans<<endl;
    return 0;
}