题目链接：台阶-Nim游戏

#include <iostream>
#include <algorithm>

using namespace std;

int main()
{
    int n;
    cin >> n;
    int res = 0;
    for(int i = 1;i <= n; i++)
    {
        int x;
        cin >> x;
        if(i % 2) res ^= x; 
    }
    
    if(res) cout << "Yes" << endl;
    else cout << "No" << endl;
    
    return 0;
}