N-th Prime Number

/*
 * Problem : Process a number.
 * Input   : One integer n.
 * Output  : The n-th prime.
 * Approach: A sieve with a safe limit.
 * Time    : O(L log log L)
 * Space   : O(L)
 * Java    : 8 or newer.
 */
import java.util.Scanner;

public class Main {
    // This method solves the task. It receives the input and returns the answer.
    static long solve(long n) {
        // Step 1: A fixed limit of 120000 is enough for n up to 10000.
        int limit = 120_000;
        boolean[] composite = new boolean[limit + 1];
        long count = 0;

        // Step 2: Sieve of Eratosthenes. For each prime p, mark its multiples as composite.
        for (int p = 2; p <= limit; p++) {
            if (!composite[p]) {
                count++;
                if (count == n) {
                    return p;
                }
                for (long multiple = (long) p * p; multiple <= limit; multiple += p) {
                    composite[(int) multiple] = true;
                }
            }
        }
        return -1;
    }

    public static void main(String[] args) {
        long n = new Scanner(System.in).nextLong();
        System.out.println(solve(n));
    }
}