#include <bits/stdc++.h>
#define DB double
#define LL long long

#define MST(a, b) memset((a), (b), sizeof(a))
#define MRK() cout << "Mark" << endl;
#define WRT(x) cout << #x << " = " << (x) << endl;
#define AUTO(s) \
    for (auto p : s) cout << p << ' ';

#define MAXN 10000
#define MAXM 10000
#define MOD 998244353
#define INF 0x3f3f3f3f
#define LLINF 0x3f3f3f3f3f3f3f3f
#define EPS 1e-5

#define _ 0
using namespace std;

void InitFactor(vector<vector<int> > &v, int x) {
    v.clear();
    v.resize(x + 1);
    for (int i = 1; i <= x; i++)
        for (int j = i; j <= x; j += i) v[j].push_back(i);
}

void InitPrimeFactor(vector<vector<int> > &v, int x) {
    v.clear();
    v.resize(x + 1);
    for (int i = 2; i <= x; i++)
        if (v[i].size() == 0)
            for (int j = i; j <= x; j += i) v[j].push_back(i);
}
vector<vector<int> > factor;

typedef int integer;
void GetFactor(vector<int> &v, integer x) {
    v.clear();
    integer i;
    for (i = 1; i * i < x; i++)
        if (x % i == 0) {
            v.push_back(i);
            v.push_back(x / i);
        }
    if (i * i == x)
        v.push_back(i);
    sort(v.begin(), v.end());
}
vector<int> v;

void GetPrimeFactor(map<integer, int> &mp, integer x) {
    mp.clear();
    integer i;
    for (i = 2; i * i <= x; i++)
        while (x % i == 0) {
            mp[i]++;
            x /= i;
        }
    if (x >= 2)
        mp[x]++;
}
map<integer, int> mp;

integer euler(integer x) {
    GetPrimeFactor(mp, x);
    integer ans = x;
    for (auto p : mp) ans = ans / p.first * (p.first - 1);
    return ans;
}

LL gcd(LL x, LL y) {
    if (x < y)
        swap(x, y);
    if (y == 0)
        return x;
    return gcd(y, x % y);
}

int main() {
    InitPrimeFactor(factor, 1300000);
    // for (int i=2;i<100;i++)
    //{
    //	cout<<i<<':';
    //	for (auto p:factor[i])
    //		cout<<p<<' ';
    //	cout<<endl;
    //}
    int n;
    cin >> n;
    int i = 2, cnt = 0;
    for (; cnt < n && i < factor.size(); i++)
        if (factor[i].size() == 1 && factor[i][0] == i) {
            /// WRT(factor
            cnt++;
        }
    // WRT(cnt);
    cout << i - 1;
    return ~~(0 ^ _ ^ 0);
}