#include
#include
using namespace std;
void solve(){
int N; cin >> N;
int count = 0;
bool prime[N+1]; memset(prime, true, sizeof(prime));
for (int i = 2; i <= N; i++) {
if (!prime[i]) continue;
for (int j = i+i; j<= N; j+=i) prime[j]=false;
if (i == 2 || i == 5) continue;
int s = 1;
for (int j = 0; j < i/2-1; j++) {
s = (s*100+1)%i;
if (s == 0 && j != i/2-2) {
s = -1;
break;
}
}
if (s==0) count++;
}
cout << count;
}
int main()
{
cin.tie(0)->sync_with_stdio(false);
solve();
return 0;
}