#include #if __has_include() #include using namespace atcoder; #endif using namespace std; /* #pragma GCC target("avx2") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") */ #define ll long long #define rep(i, n) for (ll i = 0; i < n; ++i) #define rep_up(i, a, n) for (ll i = a; i < n; ++i) #define rep_down(i, a, n) for (ll i = a; i >= n; --i) #define P pair #define pb push_back #define bit_count(x) __builtin_popcountll(x) #define gcd(a,b) __gcd(a,b) #define lcm(a,b) a / gcd(a,b) * b #define endl "\n" #define all(v) v.begin(), v.end() #define fi first #define se second #define vvvvll vector< vector > > > #define vvvll vector< vector< vector > > #define vvll vector< vector > #define vll vector #define pqll priority_queue #define pqllg priority_queue, greater> template inline void vin(vector& v) { rep(i, v.size()) cin >> v.at(i); } template using V = vector; constexpr ll INF = (1ll << 60); //constexpr ll mod = 1000000007; constexpr ll mod = 998244353; constexpr double pi = 3.14159265358979323846; template inline bool chmax(T &a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T &a, T b) { if (a > b) { a = b; return 1; } return 0; } template void pt(T val) { cout << val << "\n"; } template void pt_vll(vector &v) { ll vs = v.size(); rep(i, vs) { cout << v[i]; if (i == vs - 1) cout << "\n"; else cout << " "; } } ll mypow(ll a, ll n) { ll ret = 1; if (n == 0) return 1; if (a == 0) return 0; rep(i, n) { if (ret > (ll)(9e18 + 10) / a) return -1; ret *= a; } return ret; } long long modpow(long long a, long long n, long long mod) { long long res = 1; while (n > 0) { if (n & 1) res = res * a % mod; a = a * a % mod; n >>= 1; } return res; } long long modinv(long long a, long long m) { long long b = m, u = 1, v = 0; while (b) { long long t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } u %= m; if (u < 0) u += m; return u; } const int MAX = 10010000; long long fac[MAX], finv[MAX], inv[MAX]; // テーブルを作る前処理 void COMinit() { fac[0] = fac[1] = 1; finv[0] = finv[1] = 1; inv[1] = 1; for (ll i = 2; i < MAX; i++) { fac[i] = fac[i - 1] * i % mod; inv[i] = mod - inv[mod % i] * (mod / i) % mod; finv[i] = finv[i - 1] * inv[i] % mod; } } // 二項係数計算 long long COM(ll n, ll k) { if (n < k) return 0; if (n < 0 || k < 0) return 0; return fac[n] * (finv[k] * finv[n - k] % mod) % mod; } vector enum_div(ll n) { //約数全列挙 vector ret; for (ll i = 1; i * i <= n; ++i) { if (n % i == 0) { ret.push_back(i); if (i * i != n) { ret.push_back(n / i); } } } return ret; } void make_prime(vector &ret, ll n) { //素因数分解 ll x = n; for (ll i = 2; i * i <= x; i++) { while (n % i == 0) { n /= i; ret.push_back(i); } } if (n != 1) { ret.push_back(n); } return; } vector prime(1000010, true); vector pri(1000010); vector isprime(int N) { //素数判定 if (N >= 0) prime[0] = false; if (N >= 1) prime[1] = false; for (ll i = 2; i * i <= N; i++) { if (!prime[i]) { continue; } for (ll j = i * i; j <= N; j += i) { if (prime[j]) pri[j] = i; prime[j] = false; } } return prime; } map compression(vector v){ map ret; ll cnt = 0; sort(v.begin(),v.end()); for(ll i=0; i &ret, ll n) //素数判定 : vector isprime(int N) //約数全列挙: vector enum_div(ll n) void solve(){ ll n, m, k, cnt = 0, sum = 0, ans = 0; cin>>n; assert(2<=n&&n<=200000); vll a(n); vin(a); vll c(n); rep(i,n){ assert(0<=a[i]&&a[i]<=1000000000); c[i]=(a[i]+i)%2; if(c[i]==1) cnt++; } if(cnt!=n/2){ pt("No"); return; } vll b(n-1); //b[i]: i,i+1 に操作をした回数 rep(i,n-1){ b[i]=a[i]; a[i+1]-=a[i]; if(a[i+1]<0){ pt("No"); return; } } if(a[n-1]>0){ pt("No"); return; } ll x=0; //x:i以前の 1 の数 (最終状態) ll y=0; //y:i以前の 1 の数 (c) rep(i,n-1){ if(i%2==1) x++; if(c[i]==1) y++; if(abs(x-y)>b[i]){ pt("No"); return; }else if((b[i]-abs(x-y))%2==1){ pt("No"); return; } } pt("Yes"); } int main(){ ios::sync_with_stdio(false); cin.tie(nullptr); //cout << fixed << setprecision(16); //ll T; //cin>>T; //rep(ca,T) solve(); }