#include
#include
using namespace std;
int main() {
long long int n =5000005, i;
long long int p[n+1]={0};
p[2]=1;
vector<long long int> primes ;
primes.push_back(2);
for(i=3;i<=n;i+=2)
{
p[i]=1;
}
for(i=3;i<=n;i+=2)
{
if(p[i])
{
primes.push_back(i);
for(long long int j=i*i;j<=n;j+=i)
p[j]=0;
}
}
long long int g;
cin>>g;
cout << primes[g-1] << endl;
return 0;
}