#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; typedef long long ll; 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 T gcd(T a, T b) { a = abs(a), b = abs(b); while (b > 0) { tie(a, b) = make_pair(b, a % b); } return a; } //mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count()); constexpr long long INF = 1LL << 60; constexpr int inf = 1000000007; constexpr long long mod = 1000000007LL; //constexpr long long mod = 998244353LL; int main() { cin.tie(nullptr); ios::sync_with_stdio(false); ll n; cin >> n; vector a(n + 1); for (int i = 1; i <= n; i++) cin >> a[i]; ll cnt = 0; for (int i = n; i >= 1; i--) { if ((a[i] + cnt) % i != 0 or a[i] > i) { cout << "No" << "\n"; return 0; } cnt += (a[i] + cnt) / i; } cout << "Yes" << "\n"; return 0; }