#include #define be(v) (v).begin(),(v).end() #define pb(q) push_back(q) #define era(t) t.erase(unique(be(t)),t.end()) #define doublecout(a) cout<inline T lcm(T a,T b){return (a*b/__gcd(a,b));} int main() { cin.tie(0); ios::sync_with_stdio(false); ll n; cin>>n; ll a[n]; for(int i=0;i>a[i]; } if(n==1){ cout <=n/2;i--){ b[i]=b[n-i-1]; } for(ll i=0;i