#include<bits/stdc++.h>
using namespace std;
int n;
bool visit[1000005];
int prime[1000005];
map<int,int>mp;
int len;
int que[10];
void init_prim()
{
    memset(visit, true, sizeof(visit));
    int num = 0;
    for (int i = 2; i <= 1000000; ++i)
    {
        for(int j=i+i;j<=1000000;j=j+i)
            visit[j]=false;
    }
    for(int i=2;i<=1000000;i++)
        if(visit[i])
    {
        prime[++num]=i;
        mp[i]=num;
    }
}
void prime_(int  nn)
{
    len=0;
    for(int i=2;i*i<=nn;i++)
    {
        if(nn%i==0)
        {
            que[len++]=i;
            while(nn%i==0)
            {
                nn=nn/i;
            }
        }
    }
    if(nn>1)
        que[len++]=nn;
}
int main()
{
    init_prim();
    while(scanf("%d",&n)!=EOF)
    {
        len=0;
     memset(que,0,sizeof(que));
     if(n==1)
        printf("0\n");
     else
     {
         prime_(n);
         sort(que,que+len);
         //cout<<len<<endl;
         printf("%d\n",mp[que[len-1]]);
     }
    }
    return 0;
}