#include <iostream>
#include <vector>
#include <algorithm>
 
int main()
{
    std::vector<int> Vec;
    std::vector<int> Vec2;
    int N;
    std::cin>>N;
    for(int i=0; i<N; ++i)
    {
        int t=0;
        std::cin>>t;
        Vec.push_back(t);
     }
     std::reverse_copy(Vec.begin(), Vec.end(), std::back_inserter(Vec2));
     if(std::equal(Vec.begin(), Vec.end(), Vec2.begin()))
     {
         std::cout<<"YES";
     }
     else
         std::cout<<"NO";
     return 0;
}