#include #pragma GCC optimize("Ofast") #define _GLIBCXX_DEBUG using namespace std; using std::cout; using std::cin; using std::endl; using ll=long long; using ld=long double; ll ILL=1167167167167167167; const int INF=2100000000; const ll mod=998244353; #define rep(i,a) for (ll i=0;i using _pq = priority_queue, greater>; template ll LB(vector &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();} template ll UB(vector &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();} template bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;} template bool chmax(T &a,const T &b){if(a void So(vector &v) {sort(v.begin(),v.end());} template void Sore(vector &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});} void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";} struct XorShift { private: constexpr static double R = 1.0 / 0xffffffff; uint64_t x; public: explicit XorShift(uint64_t seed = 88172645463325252ull) : x(seed) {} template< typename T = uint64_t > inline T get() { // [0, 2^64) x ^= x << 7ull; x ^= x >> 9ull; return x; } inline uint32_t get(uint32_t r) { // [0, r) return ((uint64_t) get< uint32_t >() * r) >> 32ull; } inline uint32_t get(uint32_t l, uint32_t r) { // [l, r) return l + get(r - l); } inline double probability() { // [0.0, 1.0] return get< uint32_t >() * R; } }; template void shuffle_vector(vector &p,XorShift &table){ int L=p.size(); for(int i=0;i f(vector &p); vector op(vector &p){ int m=p.size(); vector q(m); for(int i=1;i> div(vector p){ vector> G; vector tmp; rep(i,p.size()){ if(tmp.size()==0){ if(p[i]!=0) tmp.push_back(0),tmp.push_back(p[i]); continue; } tmp.push_back(p[i]); if(p[i]==0){ G.push_back(tmp); tmp={}; } } return G; } void solve(); // rainy ~ 雨に打たれて ~ int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int t=1; //cin>>t; rep(i,t) solve(); } void solve(){ int N,T=1; cin>>N; vector p(N+2); if(T) rep(i,N) cin>>p[i+1]; else{ vector q(N); rep(i,N) q[i]=i+1; XorShift table(time(0)); shuffle_vector(q,table); rep(i,N) p[i+1]=q[i]; } if(N==2){ cout<<"0 1\n"; return ; } auto G=div(op(p)); int ans_t=0,ans_c=0; for(auto x:G){ auto tmp=f(x); chmax(ans_t,tmp.first); ans_c+=tmp.second; //for(auto y:x) cout< f(vector &p){ int l=0,r=1; int n=p.size(); rep(i,n){ if(i%2==0){ if(p[l]r) swap(l,r); return {max(l-1,n-2-r)+(r-l)/2,1}; }