#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 5;
const int INF = 2e9;
const int MOD = 1e9 + 7;
long long arr[MAXN], T[MAXN * 4];
long long gcd(long long A, long long B) {
  while (B != 0) {
    A %= B;
    swap(A, B);
  }
  return A;
}
void build(int v, int tl, int tr) {
  if (tl == tr) {
    T[v] = arr[tl];
    return;
  }
  int mid = (tl + tr) >> 1;
  build(v * 2, tl, mid);
  build(v * 2 + 1, mid + 1, tr);
  T[v] = gcd(T[v * 2], T[v * 2 + 1]);
}
void upd(int v, int tl, int tr, int pos, long long new_val) {
  if (tl == tr) {
    T[v] = new_val;
    return;
  }
  int mid = (tl + tr) >> 1;
  if (pos <= mid)
    upd(v * 2, tl, mid, pos, new_val);
  else
    upd(v * 2 + 1, mid + 1, tr, pos, new_val);
  T[v] = gcd(T[v * 2], T[v * 2 + 1]);
}
int main() {
  int N = 0;
  scanf("%d", &N);
  long long cur_gcd = 0, RES = 0;
  for (int i = 1; i <= N; i++) scanf("%lld", &arr[i]);
  build(1, 1, N);
  if (T[1] > 1) return printf("YES\n0"), 0;
  for (int i = 1; i + 1 <= N; i++) {
    if (arr[i] % 2 == 1 && arr[i + 1] % 2 == 1) {
      long long l = arr[i] - arr[i + 1], r = arr[i] + arr[i + 1];
      arr[i] = l, arr[i + 1] = r, RES++;
      upd(1, 1, N, i, l);
      upd(1, 1, N, i + 1, r);
    }
    if (T[1] > 1) return printf("YES\n%lld", RES), 0;
  }
  for (int i = 1; i + 1 <= N; i++) {
    for (int j = 1; j <= 2; j++, RES++) {
      if (T[1] > 1 || gcd(arr[i], arr[i + 1]) % 2 == 0) break;
      long long l = arr[i] - arr[i + 1], r = arr[i] + arr[i + 1];
      arr[i] = l, arr[i + 1] = r;
      upd(1, 1, N, i, l);
      upd(1, 1, N, i + 1, r);
    }
  }
  printf("YES\n");
  printf("%lld", RES);
  return 0;
}
