#include #define MOD 1000000007 #define INF (1<<30) #define INFL (1<<62) #define pe(str) return cout<<(str)<=0;i--) #define rep(i,a,b) for(int i=(a);i<(b);i++) #define rrep(i,a,b) for(int i=(b);i>=(a);i--) #define bw(a,b,c) (((a)<=(b))&&((b)<=(c))) #define hello cout<<"hello"<>n using namespace std; typedef long long ll; typedef unsigned long long ull; typedef long double ld; typedef pair pii; typedef complex point; template void dump(InputIterator first,InputIterator last,char delim=' '){ for(InputIterator it=first;it!=last;it++){ if(it!=first)cout< void swp(T &a,T &b){ T t=a; a=b; b=t; } int main(void){ int n; cin>>n; int a,b; cin>>a; if(a>=n)pe("YES"); re(i,n-1){ cin>>b; if(b