#include<stdio.h>
int main()
{
    int n,a[n],k=0;
    scanf("%d",&n);
    for (int i=0;i<n;i++) 
    {
        scanf("%d",&a[i]);
        
        for (int j=0;j<i;j++)
            a[j]>a[i]&&k++;
    }
    
    printf ("%d",k);
    return 0;
}