import java.util.*;
public class test {
public static void main(String[] args) {
System.out.println(primeFinder(13));
}
public static ArrayList primeFinder(int n) {
ArrayList<Integer> integerArray = new ArrayList<Integer>();
for (int i = 1; i <= n; i++) {
int count = 0;
for (int j = i; j >= 1; j--) {
if (i % j == 0) {
count++;
}
}
if (count == 2) {
integerArray.add(i);
}
}
return integerArray;
}
}