#include <bits/stdc++.h>
using namespace std;
int n,a[100],b[100];
int m;
int solve(int l,int r){
	if(l>=r) return 0;
	int p=(l+r)/2;
	int res=solve(l,p)+solve(p+1,r);
	int i=l,j=p+1,k=l;
	while(k<=r){
		if(j>r||(i<=p&&a[i]<=a[j])){
			b[k++]=a[j++];
		}else{
			res+=p-i+1;
			b[k++]=a[j++];
		}
	}
	for(int i=1;i<=r;++i) a[i]=b[i];
	return res; 
}
int main () {
	scanf("%d",&n);
	for(int i=1;i<=n;++i) cin>>a[i];
	m=solve(1,n);
	printf("%d",&m);
	return 0;
}