1 #include
      
        2 #include
       
         3 using namespace std ; 4 int main() 5 { 6     int a[1005] ; 7     int n ; 8     while(cin>>n,n!=0) 9     {10         while(cin>>a[0],a[0])11         {12             for(int i=1; i
        
         >a[i] ;14             stack
         
          s ;15             int num = 0 ;16             for(int i=1; i<=n; i++)17             {18                 s.push(i) ;19                 while(!s.empty()&&s.top()==a[num])20                 {21                     s.pop() ;22                     num++ ;23                 }24             }25             if(s.empty())26             cout<<"Yes"<