#include <bits/stdc++.h>
using namespace std;
long long a[100010];
bool b[100010];
long long gcd(long long a, long long b) { return a % b ? gcd(b, a % b) : b; }
int main() {
  long long n, t;
  scanf("%lld", &n);
  for (int i = 1; i <= n; i++) {
    scanf("%lld", &a[i]);
    b[i] = a[i] % 2;
  }
  long long ans = gcd(abs(a[1]), abs(a[2]));
  for (int i = 3; i <= n; i++) ans = gcd(ans, abs(a[i]));
  if (ans > 1)
    printf("YES\n0\n");
  else {
    int num = 0;
    for (int i = 1; i < n; i++)
      while (b[i] == 1) {
        if (b[i + 1] == 1) {
          b[i] = 0;
          b[i + 1] = 0;
        } else {
          b[i + 1] = 1;
        }
        ++num;
      }
    if (b[n] == 1) num += 2;
    printf("YES\n%d\n", num);
  }
  return 0;
}
