//双指针
import java.util.Arrays;
import java.util.Scanner;
public class Main {
public static void main(String args[]) {
Scanner scanner=new Scanner(System.in);
int n=scanner.nextInt();
int a[]=new int [(int)1e5+10];
int b[]=new int [(int)1e5+10];
int c[]=new int [(int)1e5+10];
for (int i = 0; i [HTML_REMOVED]a[i]&&i<n)i;
cnt1=i;
// System.out.println(“cnt1=”+cnt1);
while(c[k]<=b[j]&&k<n)k;
cnt2=n-k;
// System.out.println(“cnt2=”+cnt2);
cnt+=(cnt1*cnt2);
}
System.out.println(cnt);
}
}