sieve of erathonese given tle
import java.util.*;
public class Main {
public static boolean a[]= new boolean[100000001];
public static void main(String args[]) {
Scanner sc= new Scanner(System.in);int n=sc.nextInt();
for(int i=0;i<=100000000;i++){
a[i]=true;
}
a[0]=false;a[1]=false;
for(int p=2;p*p<=100000000;p++){
for(int j=p*p;j<=100000000;j=j+p){
if(a[j]){
a[j]=false;
}
}
}
//ArrayList<Integer> p1=new ArrayList<>();
int count=0;
for(int i=2;i<=100000000;i++){
if(a[i]){
count++;
}
if(count==n){
System.out.println(i);break;
}
}
}
}
my solution