Sum of Prime Numbers up to N

import java.util.*;
class Main{
public static boolean isPrime(int n){
if(n<=1) return false;
for(int i=2;i<=Math.sqrt(n);i++){
if(n%i==0) return false;
}
return true;
}
public static void main(String[] args){
Scanner sc=new Scanner(System.in);
int n=sc.nextInt();
int sum=0;
for(int i=2;i<=n;i++){
if(isPrime(i))
sum+=i;
}
System.out.println(sum);
}
}