代码:
1 import java.util.*; 2 public class Main { 3 public static void main (String [] args) { 4 Scanner s=new Scanner(System.in); 5 int n=s.nextInt(); 6 int sum=0; 7 for(int i=1;i<=n;i+=2) { 8 sum+=i; 9 } 10 System.out.println(sum); 11 } 12 }