#include using namespace std; #define FOR(i,a,b) for(int i=(a);i<(b);++i) #define REP(i,n) FOR(i,0,n) #define ALL(v) begin(v),end(v) template inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; } template inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; } using ll = long long; using pii = pair; constexpr ll INF = 1ll<<30; constexpr ll longINF = 1ll<<60; constexpr ll MOD = 1000000007; constexpr bool debug = false; //---------------------------------// std::vector sieve(int n) { std::vector res; std::vector is_prime(n + 1, true); is_prime[0] = is_prime[1] = false; for (int i = 2; i * i <= n; i++) { if (!is_prime[i]) continue; for (int j = i * i; j <= n; j += i) is_prime[j] = false; } for (int i = 2; i <= n; ++i) if (is_prime[i]) res.emplace_back(i); return res; } int main() { int N; cin >> N; if (N == 1) puts("1"); else { vector prime; for (int i : sieve(110000)) { if (i <= 100000) continue; prime.emplace_back(i); } vector suteki; REP(i, prime.size()) FOR(j, i + 1, prime.size()) suteki.emplace_back((ll)prime[i] * prime[j]); sort(ALL(suteki)); cout << suteki[N - 1] << endl; } }