/* Kristoffer Hansen. arnsfelt@daimi.au.dk */

#include <iostream>
#include <stack>

const int MAXN = 1000;

int n;
int C[MAXN];
stack<int> S;

int main()
{
  int i,j;
  while (cin >> n && n>0) {
    while (cin >> C[0] && C[0]>0) {
      for (i=1; i<n; i++)
	cin >> C[i];
      S = stack<int>();
      for (i=0, j=1; j<=n; j++) {
	S.push(j);
	while (!S.empty() && S.top()==C[i]) {
	  S.pop();
	  i++;
	}
      }
      cout << (i==n ? "Yes\n" : "No\n");
    }
    cout << endl;
  }
  return 0;
}