#include using namespace std; #define rep(i, n) for(long long i=0;i<(long long)(n);i++) #define REP(i,k,n) for(long long i=k;i<(long long)(n);i++) #define pb emplace_back #define lb(v,k) (lower_bound(all(v),(k))-v.begin()) #define ub(v,k) (upper_bound(all(v),(k))-v.begin()) #define fi first #define se second #define pi M_PI #define PQ(T) priority_queue #define SPQ(T) priority_queue,greater> #define dame(a) {out(a);return 0;} #define decimal cout< P; typedef tuple PP; typedef tuple PPP; using vi=vector; using vvi=vector; using vvvi=vector; using vvvvi=vector; using vp=vector

; using vvp=vector; using vb=vector; using vvb=vector; const ll inf=1001001001001001001; const ll INF=1001001001; const ll mod=1000000007; const double eps=1e-10; template bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;} template bool chmax(T&a,T b){if(a void out(T a){cout< void outp(T a){cout<<'('< void outvp(T v){rep(i,v.size())cout<<'('< void outvvp(T v){rep(i,v.size())outvp(v[i]);} template void outv(T v){rep(i,v.size()){if(i)cout<<' ';cout< void outvv(T v){rep(i,v.size())outv(v[i]);} template bool isin(T x,T l,T r){return (l)<=(x)&&(x)<=(r);} template void yesno(T b){if(b)out("yes");else out("no");} template void YesNo(T b){if(b)out("Yes");else out("No");} template void YESNO(T b){if(b)out("YES");else out("NO");} template void outset(T s){auto itr=s.begin();while(itr!=s.end()){if(itr!=s.begin())cout<<' ';cout<<*itr;itr++;}cout<<'\n';} void outs(ll a,ll b){if(a>=inf-100)out(b);else out(a);} ll gcd(ll a,ll b){if(b==0)return a;return gcd(b,a%b);} ll modpow(ll a,ll b){ll res=1;a%=mod;while(b){if(b&1)res=res*a%mod;a=a*a%mod;b>>=1;}return res;} int main(){ ll n;cin>>n; vi v(n);rep(i,n)cin>>v[i]; vi id(n); rep(i,n){ if(i==0)id[i]=1; else if(i==n-1)id[i]=0; else if(v[i-1]1&&a==0)a=1; if(c>1&&b==0)b=1; ll tmp2=min(a,b); tmp+=tmp2; a-=tmp2;b-=tmp2; ans2++; tmp+=a+b; chmax(ans1,tmp); l=r; } cout<