#include <bits/stdc++.h>
using namespace std;

int main()
{
	int N;
	cin >> N;
	vector<int> A( N );
	for( int i = 0; i < N; i++ ) cin >> A[i];

	int ans = 0;
	for( int i = 0; i < N; i++ ) {
		int f = 0;
		for( int j = i; j < N - 1; j++ ) {
			if( (f ^ A[j]) == 0 ) break;
			ans++;
			f = 1 - f;
		}
	}

	cout << ans << endl;
}