#include <algorithm>
#include <cstdint>
#include <iostream>
#include <string>
#include <vector>

namespace {

using u64 = std::uint64_t;
using u128 = unsigned __int128;

struct Options {
    int target = 2000;
    bool run_checkpoints = true;
};

bool parse_int_after_prefix(const std::string& arg, const std::string& prefix, int& value) {
    if (arg.rfind(prefix, 0U) != 0U) {
        return false;
    }
    const std::string tail = arg.substr(prefix.size());
    if (tail.empty()) {
        return false;
    }

    int parsed = 0;
    for (char c : tail) {
        if (c < '0' || c > '9') {
            return false;
        }
        parsed = parsed * 10 + static_cast<int>(c - '0');
    }
    value = parsed;
    return true;
}

bool parse_arguments(int argc, char** argv, Options& options) {
    for (int i = 1; i < argc; ++i) {
        const std::string arg(argv[i]);
        if (arg == "--skip-checkpoints") {
            options.run_checkpoints = false;
            continue;
        }
        if (parse_int_after_prefix(arg, "--target=", options.target)) {
            continue;
        }

        std::cerr << "Unknown argument: " << arg << '\n';
        return false;
    }

    return options.target >= 1;
}

u64 mul_mod(u64 a, u64 b, u64 mod) {
    return static_cast<u64>((static_cast<u128>(a) * static_cast<u128>(b)) % mod);
}

u64 pow_mod(u64 base, u64 exp, u64 mod) {
    u64 result = 1 % mod;
    base %= mod;
    while (exp > 0) {
        if ((exp & 1ULL) != 0ULL) {
            result = mul_mod(result, base, mod);
        }
        base = mul_mod(base, base, mod);
        exp >>= 1ULL;
    }
    return result;
}

bool is_prime(u64 n) {
    if (n < 2) {
        return false;
    }
    for (u64 p : {2ULL, 3ULL, 5ULL, 7ULL, 11ULL, 13ULL, 17ULL, 19ULL, 23ULL, 29ULL, 31ULL, 37ULL}) {
        if (n == p) {
            return true;
        }
        if (n % p == 0ULL) {
            return false;
        }
    }

    u64 d = n - 1;
    int s = 0;
    while ((d & 1ULL) == 0ULL) {
        d >>= 1ULL;
        ++s;
    }

    for (u64 a : {2ULL, 3ULL, 5ULL, 7ULL, 11ULL, 13ULL, 17ULL}) {
        if (a % n == 0ULL) {
            continue;
        }
        u64 x = pow_mod(a, d, n);
        if (x == 1ULL || x == n - 1) {
            continue;
        }

        bool witness = true;
        for (int r = 1; r < s; ++r) {
            x = mul_mod(x, x, n);
            if (x == n - 1) {
                witness = false;
                break;
            }
        }
        if (witness) {
            return false;
        }
    }

    return true;
}

u64 solve(const int target) {
    if (target == 1) {
        return 1;
    }
    if (target == 2) {
        return 2;
    }

    std::vector<u64> values = {1, 2};

    for (u64 k = 2; static_cast<int>(values.size()) < target; ++k) {
        const u64 a = 6 * k - 1;
        if (is_prime(a) && is_prime(6 * k + 1) && is_prime(12 * k + 5)) {
            values.push_back(3 * k * (k - 1) + 2);
            if (static_cast<int>(values.size()) == target) {
                break;
            }
        }

        if (is_prime(a) && is_prime(6 * k + 5) && is_prime(12 * k - 7)) {
            values.push_back(3 * k * (k + 1) + 1);
            if (static_cast<int>(values.size()) == target) {
                break;
            }
        }
    }

    return values[static_cast<std::size_t>(target - 1)];
}

bool run_checkpoints() {
    if (solve(10) != 271ULL) {
        std::cerr << "Checkpoint failed for target=10" << '\n';
        return false;
    }
    return true;
}

}  // namespace

int main(int argc, char** argv) {
    Options options;
    if (!parse_arguments(argc, argv, options)) {
        return 1;
    }
    if (options.run_checkpoints && !run_checkpoints()) {
        return 2;
    }

    std::cout << solve(options.target) << '\n';
    return 0;
}