#include using namespace std; #define rep(i, n) for(int(i) = 0; (i) < (n); (i)++) #define FOR(i, m, n) for(int(i) = (m); (i) < (n); (i)++) #define All(v) (v).begin(), (v).end() #define pb push_back #define MP(a, b) make_pair((a), (b)) template vector make_vec(size_t a, T val) { return vector(a, val); } template auto make_vec(size_t a, Ts... ts) { return vector(a, make_vec(ts...)); } using ll = long long; using pii = pair; using pll = pair; using Graph = vector>; template struct edge { int to; T cost; edge(int t, T c) : to(t), cost(c) {} }; template using WGraph = vector>>; const int INF = 1 << 30; const ll LINF = 1LL << 60; const int MOD = 1e9 + 7; int main() { int N; cin >> N; vector A(N); rep(i, N) cin >> A[i]; while(A.back() == 0) A.pop_back(); N = A.size(); if(A[N - 1] != N) { cout << "No" << endl; } else { bool ok = 1; ll add = 0; for(int i = N - 1; i >= 0; i--) { if((A[i] + add) % (i + 1) == 0) { add += (A[i] + add) / (i + 1); } else { ok = 0; break; } } cout << (ok ? "Yes" : "No") << endl; } }