/* -*- coding: utf-8 -*-
 *
 * 1765.cc:  No.1765 While Shining - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 200000;

/* typedef */

typedef long long ll;

/* global variables */

int as[MAX_N], dp[MAX_N][2];

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", as + i);

  ll sum = 0;
  dp[n - 1][0] = dp[n - 1][1] = 0;
  for (int i = n - 2; i >= 0; i--) {
    for (int j = 0; j < 2; j++)
      dp[i][j] = (as[i] ^ j) ? 1 + dp[i + 1][j ^ 1] : 0;
    sum += dp[i][0];
  }

  printf("%lld\n", sum);
  return 0;
}