#include<iostream>

 #include<cstdio>

 #include<cstring>

 #include<cmath>

 #include<algorithm>

 #define INF (2139062143)

 using namespace std;

 const int MAXN=;

 void read(int &n)

 {

     char c='+';int x=;bool flag=;

     while(c<''||c>''){c=getchar();if(c=='-')flag=;}

     while(c>=''&&c<='')

     {x=x*+c-;c=getchar();}

     flag==?n=-x:n=x;

 }

 int n;

 int a[MAXN];

 int dp[MAXN][MAXN];

 int main()

 {

     while(scanf("%d",&n)==)

     {

         memset(a,,sizeof(a));

         for(int i=;i<=n;i++)

             read(a[i]);

         memset(dp,,sizeof(dp));

         dp[][]=-;

         for(int i=;i<=n;i++)

         {

             for(int j=;j<=i;j++)

             {

                 if(dp[i][j]!=INF)

                 {

                     if(a[i]<a[i+])

                         if(dp[i+][j+]>dp[i][j])

                             dp[i+][j+]=dp[i][j];

                     if(dp[i][j]<a[i+])

                         if(dp[i+][i+-j]>a[i])

                             dp[i+][i+-j]=a[i];

                 }

             }

         }

         if(dp[n][n/]==INF)

             printf("No!\n");

         else

             printf("Yes!\n");

     }

     return ;

 }