取数游戏II

传送门

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define re register
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define P pair<int,int>
const int N=1e4;
const int mod=1e9+7;
void read(int &a)
{
    a=0;
    int d=1;
    char ch;
    while(ch=getchar(),ch>'9'||ch<'0')
        if(ch=='-')
            d=-1;
    a=ch-'0';
    while(ch=getchar(),ch>='0'&&ch<='9')
        a=a*10+ch-'0';
    a*=d;
}
void write(int x)
{
    if(x<0)
        putchar(45),x=-x;
    if(x>9)
        write(x/10);
    putchar(x%10+'0');
}
int a[25];
int main()
{
    int n;
    read(n);
    int cur;
    for(re int i=1;i<=n;i++)
        read(a[i]);
    int t1=0,t2=0;
    for(re int i=1;i<=n;i++)
    {
        if(a[i]==0)
            break;
        t1++;
    }
    for(re int i=n;i>=1;i--)
    {
        if(a[i]==0)
            break;
        t2++;
    }
    if(t1&1||t2&1)
        puts("YES");
    else
        puts("NO");
    return 0;
}