#include <bits/stdc++.h>
const int N = 100050;
const int inf = 1e9 + 7;
int gcd(int x, int y) { return x ? gcd(y % x, x) : y; }
int min(int a, int b) { return a > b ? b : a; }
int dp[N][2], a[N];
int main() {
  int n, i, g = 0;
  scanf("%i", &n);
  for (i = 1; i <= n; i++) scanf("%i", &a[i]), g = gcd(g, a[i]), a[i] %= 2;
  if (g > 1) return printf("YES\n0\n"), 0;
  for (i = 0; i < N; i++) dp[i][0] = dp[i][1] = inf;
  dp[0][0] = 0;
  for (i = 1; i <= n; i++) {
    if (a[i]) {
      dp[i][0] = dp[i - 1][1] + 1;
      dp[i][0] = min(dp[i][0], dp[i - 1][0] + 2);
      dp[i][1] = dp[i - 1][0];
    } else {
      dp[i][0] = dp[i - 1][0];
      dp[i][0] = min(dp[i][0], dp[i - 1][1] + 2);
    }
  }
  printf("YES\n");
  printf("%i\n", dp[n][0]);
  return 0;
}
