/*
演算法競賽入門 LRJ 例題6-2（UVa 514）Rails
*/

#include<iostream>
#include<cstdio>
#include<cstring>
#include<stack>
#include<map>
#include<queue>
#include<cmath>
#include<algorithm>
#include<deque>
typedef long long LL;
using namespace std;
#pragma comment(linker, "/STACK:102400000,102400000")
const int INF=0x3f3f3f3f;
const int N = 10010;

int a[N];
stack<int> Q;
int main()
{
    int n;
    while(~scanf("%d",&n), n)
    {
        while(~scanf("%d",&a[1]))
        {
            if(a[1] == 0)
                break;
            for(int i = 2; i <= n; i++)
                scanf("%d",&a[i]);
            int in = 1,out = 1;
            while(out <= n)
            {
                if(in == a[out])
                    in++,out++;
                else if(!Q.empty() && Q.top() == a[out])
                    Q.pop(),out++;
                else if(in < n)
                    Q.push(in++);
                else
                    break;
            }
            if(out != n+1)
                printf("No\n");
            else
                printf("Yes\n");
        }
        puts("");
    }
    return 0;
}