40 lines
787 B
C++
40 lines
787 B
C++
#include <cstring>
|
|
#include <cmath>
|
|
#include <algorithm>
|
|
#include <iostream>
|
|
#include <cstdio>
|
|
using namespace std;
|
|
#define maxn 1000010
|
|
bool prime[maxn];
|
|
void Prime()
|
|
{
|
|
memset(prime,true,sizeof(prime));
|
|
prime[0]=prime[1]=0;
|
|
for(int i=2;i*i<maxn;i++)
|
|
if(prime[i])
|
|
for(int j=2*i;j<maxn;j+=i)
|
|
prime[j]=0;
|
|
}
|
|
int main()
|
|
{
|
|
Prime();
|
|
int n,ans,p;
|
|
while(scanf("%d",&n)!=EOF)
|
|
{
|
|
ans=0;
|
|
for(int i=1;;i++)
|
|
{
|
|
int tmp=3*i*i+3*i+1;
|
|
if(tmp>n)
|
|
break;
|
|
if(prime[tmp])
|
|
ans++;
|
|
}
|
|
if(ans)
|
|
printf("%d\n",ans);
|
|
else
|
|
printf("No Special Prime!\n");
|
|
}
|
|
return 0;
|
|
}
|