#include<bits/stdc++.h>
using namespace std;
int n,a[100005];
int ans;
signed main(){
	cin>>n;
	for(int i=1;i<=n;i++)
		cin>>a[i];
	for(int i=1;i<=n;i++){
		int t=0;
		for(int j=i;j<=n;j++){
			if(a[i]==0&&t==0&&a[j]==0) t=1;
			if((a[i]==1&&a[j]==0)||(a[i]==0&&a[j]==1)) t=2;
			ans+=t;
		}
	}
	cout<<ans;
    return 0;
}