#include<cstdio>

 #include<cstdlib>

 #include<cstring>

 #include<iostream>

 #include<algorithm>

 using namespace std;

 #define Maxm 1000010

 #define LL long long

 LL pri[Maxm],pl,mu[Maxm];

 bool vis[Maxm];

 void init()

 {

     for(LL i=;i<=Maxm-;i++)

     {

         if(!vis[i]) pri[++pl]=i,mu[i]=-;

         for(LL j=;j<=pl;j++)

         {

             if(pri[j]*i>Maxm-) break;

             vis[pri[j]*i]=;

             if(i%pri[j]==) mu[pri[j]*i]=;

             else mu[i*pri[j]]=-mu[i];

             if(i%pri[j]==) break;

         }

     }

 }

 LL n;

 bool check(LL x)

 {

     LL ans=;

     for(LL i=;i*i<=x;i++)

     {

         ans+=x/(i*i)*(-mu[i]);

     }

     return ans>=n;

 }

 int main()

 {

     init();

     scanf("%lld",&n);

     LL l=,r=30000000000LL;

     while(l<r)

     {

         LL mid=(l+r)>>;

         if(check(mid)) r=mid;

         else l=mid+;

     }

     printf("%lld\n",l);

     return ;

 }