#include <bits/stdc++.h>
using namespace std;
const int c_INF = 111111111;
const int c_mINF = -111111111;
const int c_YET = -1;
const int c_Dx[4] = {0, 0, 1, -1};
const int c_Dy[4] = {1, -1, 0, 0};
int main() {
  int N, A[100005];
  int sum = 0;
  bool end = false;
  scanf("%d", &N);
  for (int i = 0; i < N; i++) {
    scanf("%d", &A[i]);
    sum += A[i];
  }
  if (N >= 1000)
    printf("Yes");
  else
    printf("No");
}
