#include<bits/stdc++.h>
#define ll long long
using namespace std;
int cnt[1000000];
int main(){
ios::sync_with_stdio(0);
int n;
cin>>n;
int ret = 0;
int cur = 0;
int first = -1;
int last = 0;
for (int i=0;i<n-1;i++) {
int x;
cin>>x;
if (x==0) {
if (first!=-1) {
ret+=max(cur - (first%2==0), 0);
}
if (first!=0 && last!=0) ret++;
first = -1;
cur = 0;
} else {
if (first==-1)
first = x;
if (x%2 && last!=0 && last%2==0) {
cur++;
}
}
last=x;
}
if (first!=-1) {
ret+=max(cur - (first%2==0), 0);
}
cout<<ret<<endl;
}
Copy