#include <bits/stdc++.h>
using namespace std;
int gcd(int a, int b) {
  while (a != 0) {
    int c = a;
    a = b % a;
    b = c;
  }
  return b;
}
vector<int> adj[3000];
vector<int> getAllDivisors(int num) {
  vector<int> divs;
  int square_root = (int)sqrt(num) + 1;
  for (int i = 1; i < square_root; i++) {
    if (num % i == 0) {
      if (i * i != num) {
        divs.push_back(i);
      }
      divs.push_back(num / i);
    }
  }
  return divs;
}
class ChangingChange {
 public:
};
long long int mod_pow(long x, int y) {
  long long int r = 1;
  while (y > 0) {
    if (y % 2 == 1) {
      r = (r * x) % (1000000007);
    }
    x = (x * x) % (1000000007);
    y /= 2;
  }
  return r;
}
int main() {
  ChangingChange temp;
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int n;
  vector<int> arr;
  cin >> n;
  for (int i = 0; i < n; i++) {
    int temp;
    cin >> temp;
    arr.push_back(temp);
  }
  int moves = 0;
  int GCD = arr[0];
  for (int i = 1; i < n; i++) {
    GCD = gcd(GCD, arr[i]);
  }
  if (GCD > 1) {
    cout << "YES" << '\n' << moves;
    return 0;
  }
  for (int i = 0; i < n - 1; i++) {
    if ((arr[i] % 2 == 1) && (arr[i + 1] % 2 == 1)) {
      arr[i] = 2, arr[i + 1] = 2;
      moves++;
    }
  }
  for (int i = 0; i < n; i++) {
    if (arr[i] % 2) {
      moves += 2;
    }
  }
  cout << "YES" << '\n' << moves;
  return 0;
}
