#include <bits/stdc++.h>
using namespace std;
int a[1555555], n, i, j, gc, ans, t;
int gcd(int x, int y) {
  if (y == 0) {
    return x;
  } else {
    return gcd(y, x % y);
  }
}
int main() {
  cin >> n;
  for (i = 0; i < n; i++) {
    scanf("%d", &a[i]);
  }
  for (i = 0; i < n; i++) {
    gc = gcd(gc, a[i]);
  }
  if (gc > 1) {
    cout << "YES" << endl;
    cout << 0;
  } else {
    cout << "YES" << endl;
    for (i = 0; i < n - 1; i++) {
      while (abs(a[i]) % 2 == 1) {
        ans++;
        t = a[i];
        a[i] = a[i] - a[i + 1];
        a[i + 1] = t + a[i + 1];
      }
    }
    while (abs(a[n - 1]) % 2 == 1) {
      ans++;
      t = a[n - 2];
      a[n - 2] = a[n - 2] - a[n - 1];
      a[n - 1] = t + a[n - 1];
    }
    cout << ans;
  }
  return 0;
}
