#include using namespace std; using Int = long long; const char newl = '\n'; template inline void chmin(T1 &a,T2 b){if(a>b) a=b;} template inline void chmax(T1 &a,T2 b){if(a void drop(const T &x){cout< vector read(size_t n){ vector ts(n); for(size_t i=0;i>ts[i]; return ts; } //INSERT ABOVE HERE signed main(){ cin.tie(0); ios::sync_with_stdio(0); Int n; cin>>n; auto cs=read(n); while(cs.back()==0) cs.pop_back(); n=cs.size(); Int cnt=0; for(Int i=n;i>0;i--){ if((cs[i-1]+cnt)%i) drop("No"); cnt+=(cs[i-1]+cnt)/i; } drop("Yes"); return 0; }