#include<bits/stdc++.h>
//#pragma GCC optimize(2)
#define int long long
#define INF LLONG_MAX
#define _INF LLONG_MIN
#define ios ios::sync_with_stdio(0),cout.tie(0),cin.tie(0);
using namespace std;
const int N=0;
int c(int a){
    for(int i=2;i<=sqrt(a);i++)if(!a%i)return 0;
    return 1;
}
signed main(){
    ios
    int biao[30001];
    int t=1;
    int n;
    cin>>n;
    for(int i=1;i<=30000;i+=2)if(c(i))biao[t++]=i;
    cout<<biao[n];
    //NO COPY!
    return 0;
}