#include <iostream.h>
#include <stdio.h>
const STACK_INIT_SIZE = 1005;
const STACKINCREMENT = 10;
typedef int SElemType;
typedef struct
{
	SElemType * elem;
	int top;
	int stacksize;
	int increment;
}SqStack;

void InitStack_Sq(SqStack &S,int maxsize = STACK_INIT_SIZE,int incresize = STACKINCREMENT)
{
	S.elem = new SElemType[maxsize];
	S.top = 0;
	S.stacksize = maxsize;
	S.increment = incresize;
}

void DestroyStack_Sq(SqStack &S)
{
	delete [] S.elem;
	S.top = 0;
	S.stacksize = 0;
	S.increment = 0;
}
void ClearStack_Sq(SqStack &S)
{
	S.top = 0;
}
bool StackEmpty_Sq(SqStack S)
{
	if(!S.top)
		return true;
	else
		return false;
}
int StackLength_Sq(SqStack S)
{
	return S.top;
}
void GetTop_Sq(SqStack S,SElemType &e)
{
	e = S.elem[S.top - 1];
}
void Push_Sq(SqStack &S,SElemType e)
{
	S.elem[S.top++] = e;
}
void Pop_Sq(SqStack &S,SElemType &e)
{
	e = S.elem[--S.top];
}
void StackTraverse_Sq(SqStack S)
{
	int i;
	for(i = 0; i < S.top; i++)
	{
		cout << S.elem[i] <<endl;
	}
}

int main()
{
	int n;
	SqStack S;
	InitStack_Sq(S);
	int *p;
	int i, j, flag, k;
	while(cin>>n && n){
		ClearStack_Sq(S);
		p = new int[n];
		while(1){
			flag = 1;
			for(i = 0; i < n; i++){
				cin>>p[i];
			if(!p[0])
				break;
			}
			if(!p[0])
				break;
			i = 1;
			for(j = 0; j < n; j++){
				if(!StackEmpty_Sq(S)){
					GetTop_Sq(S, k);
					if(p[j] < k){
						flag = 0;
						break;
					}
					else if(p[j] == k)
						Pop_Sq(S,k);
				}
				if(p[j] > i )
					for(i = i+1; i < p[j]; i++)
						Push_Sq(S, i);
			}
			
			if(flag == 0)
				cout<<"No"<<endl;
			else
				cout<<"Yes"<<endl;
			fflush(stdin);			
		}//while
		printf("\n");
		delete [] p;
	}//while
	return 1;
}