/// Frail the skin is dry and pale
#pragma GCC optimize("O3")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("avx,avx2,fma")
using namespace std;
#include "bits/stdc++.h"
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>
using namespace __gnu_pbds;
using namespace __gnu_cxx;
using ll = long long;
using ii = pair<int, int>;
template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define pb push_back
#define F first
#define S second
#define f(i, a, b) for(int i = a; i < b; i++)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define sz(x) (int)(x).size()
#define mp make_pair
const int N = 5e4 + 5, LG = 18, MOD = 31607;
const double PI = acos(-1);
void doWork() {
int n;
cin >> n;
n--;
vector<int> a(n);
f(i,0,n) cin >> a[i];
bool f = false;
int ans = 0;
for(int i = 0; i < n;i++) {
if(a[i] == 0) {
if(f) {
ans += 1;
f = false;
}
} else if(a[i] % 2 == 1) {
f = true;
} else if(a[i] % 2 == 0) {
if(f) {
ans += 1;
f = false;
} else {
f = true;
}
}
}
cout << ans + f - 1 << '\n';
}
int32_t main() {
#ifdef ONLINE_JUDGE
ios_base::sync_with_stdio(0);
cin.tie(0);
#endif // ONLINE_JUDGE
int t = 1;
// cin >> t;
while (t--) {
doWork();
}
return 0;
}
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