#include<iostream>
#include<cstdio>
using namespace std;
const int N = 1010, M = 2e6 + 10;
int n, A[N];
int T, B[M];
int fst, lst, pre[N], nex[N], r;
int getlst(){
	if(r == 0) return lst;
	return fst;
}
int getfst(){
	if(r == 0) return fst;
	return lst;
}
int getsec(){
	if(r == 0) return nex[fst];
	return pre[lst];
}
int getnex(int x){
	if(r == 0) return nex[x];
	return pre[x];
}
void opt1(){
	B[++T] = 1;
	r ^= 1;
}
void opt2(){
	B[++T] = 2;
	int x = getsec(), l = getlst(), f = getfst(), y = getnex(x);
	if(r == 0){
		pre[x] = l;
		nex[l] = x;
		pre[y] = f;
		nex[f] = y;
		lst = x;
	}else{
		nex[x] = l;
		pre[l] = x;
		nex[y] = f;
		pre[f] = y;
		fst = x;
	}
}
void opt3(){
	B[++T] = 3;
	int x = getsec(), l = getlst(), f = getfst();
	if(r == 0){
		pre[f] = l;
		nex[l] = f;
		pre[x] = 0;
		nex[f] = 0;
		lst = f;
		fst = x;
	}else{
		nex[f] = l;
		pre[l] = f;
		nex[x] = 0;
		pre[f] = 0;
		lst = x;
		fst = f;
	}
}
void print(){
	printf("\n");
	int u = getfst();
	while(u != getlst()){
		printf("%d ",u);
		u = getnex(u);
	}
	printf("%d\n",getlst());
}
void init(){
	for(int i = 1; i <= n; i += 1){
		pre[i] = i - 1;
		if(i != n) nex[i] = i + 1;
	}
	fst = 1, lst = n;
}
int main(){
	scanf("%d",&n);
	for(int i = 1; i <= n; i += 1)
		scanf("%d",&A[i]);
	init();
	if(A[1] == 1) opt1();
	else while(getlst() != A[1]) opt2();
	for(int i = 2; i < n - 1; i += 1){
		if(getfst() == A[i]){
			opt2();
			opt1();
			while(getlst() != A[1]) opt2();
			if(i == n - 2){
				opt1();
				break;
			}else{
				opt2();
				opt1();
				while(getlst() != A[i]) opt2();
			}
		}else{
			while(getlst() != A[i]) opt2();
			opt1();
			while(getsec() != A[i - 1]) opt2();
			opt1();
		}
		//print();
	}
	if(getfst() == A[n]){
		opt2();
		opt3();
	}else if(getfst() != A[1]){
		opt2();
		opt1();
		while(getlst() != A[1]) opt2();
		opt1();
	}
	printf("%d\n",T);
	for(int i = 1; i <= T; i += 1)
		printf("%d ",B[i]);
	//print();
	return 0;
}