C++ :

#include <iostream>
#include <cmath>
using namespace std;
int isPrime(int n)
{
	int i,j=sqrt(n);
	for(i=2;i<=j;i++)
		if(n%i==0) return 0;
	return 1;
}
int main()
{
	int i,n,cnt=1;
	long long mul=2;//乘积 
	cin>>n;
	for(i=3;cnt!=n;i+=2)
	{
		if(isPrime(i))
		{
			mul=mul*i%50000;
			cnt++;
		}
	}
	cout<<mul;
	return 0;
}

Java :

import java.util.Scanner;


public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int i,count=1;
		long mul=2;
		for(i=3;count!=n;i+=2) {
			if(isPrime(i)) {
				mul = mul*i%50000;
				count++;
			}
		}
		System.out.println(mul);
	}
	static boolean isPrime(int n) {
		for(int i=2;i*i<=n;i++) {
			if(n%i == 0)
				return false;
		}
		return true;
	}
}