#include <iostream>
typedef long long ll;
ll m,n,t,ans = 0;
int main(){
	std::ios::sync_with_stdio(false);
	std::cin >> n >> m;
	for(ll i = 0 ; i < n ; ++i){
		std::cin >> t;
		ans += t * (n - i);
	}
	if(ans >= m)
		std::cout << "Yes";
	else
		std::cout << "No";
	return 0;
}