#include <bits/stdc++.h>
using namespace std;
int gcd(int x, int y) { return y == 0 ? x : gcd(y, x % y); }
int a[1500000];
int main() {
  int n;
  while (~scanf("%d", &n)) {
    for (int i = 0; i < n; i++) scanf("%d", &a[i]);
    int gc = 0;
    for (int i = 0; i < n; i++) gc = gcd(gc, a[i]);
    if (gc > 1) {
      printf("YES\n0\n");
    } else {
      printf("YES\n");
      int output = 0;
      for (int i = 0; i < n - 1; i++) {
        while (abs(a[i]) % 2 == 1) {
          output++;
          int tmp = a[i];
          a[i] = a[i] - a[i + 1];
          a[i + 1] = tmp + a[i + 1];
        }
      }
      while (abs(a[n - 1]) % 2 == 1) {
        output++;
        int tmp = a[n - 2];
        a[n - 2] = a[n - 2] - a[n - 1];
        a[n - 1] = tmp + a[n - 1];
      }
      printf("%d\n", output);
    }
  }
}
