Read a number from the user and Display sum of first n natural numbers

import java.util.*;

class Sum_of_n_natural_numbers{

public static void main(String args[]){

System.out.print("Enter the number upto the sum is needed");

Scanner sc= new Scanner(System.in);

int n = sc.nextInt();

int sum=0;

if(n>=1)

{

for(int i=1; i<=n;i++)

{

sum=sum+i;

}

}

System.out.println(sum);

}}