1 //#define LOCAL 2 #include<cstdio> 3 #include<cstring> 4 #include<cstdlib> 5 #include<stack> 6 using namespace std; 7 const int maxn=1005; 8 stack<int>train; 9 int ss[maxn];10 int main()11 {12   #ifdef LOCAL13      freopen("test.in","r",stdin);14    #endif15  int n,k;16  while(scanf("%d",&n)&&n>0)17  {18      while(1)19     {20       scanf("%d",&ss[1]);21       if(ss[1]==0)break;22      for(int i=2;i<=n;i++)23          scanf("%d",ss+i);24      while(!train.empty())25            train.pop();26       k=1;27     for(int i=1;i<=n;i++)28     {29          train.push(i);30          while(!train.empty()&&train.top()==ss[k])31       {32           k++;33           train.pop();34       }35     }36     if(train.empty())printf("Yes\n");37     else printf("No\n");38     }39  }40  return 0;41 }