#include <bits/stdc++.h>   using namespace std;   bool sePuede(int rango[], int x) {     if (x % 2 == 1 && rango[0] == 1 && rango[x - 1] == 1) return true;     return false;   }   int main() {     int x = 0;     int impar = 0;     cin >> x;     int rango[x];     for (int y = 0; y < x; y++) {       cin >> rango[y];       rango[y] = rango[y] % 2;     }     if (sePuede(rango, x))       cout <<  YES  << endl;     else       cout <<  NO  << endl;   }   