#include <bits/stdc++.h>
using namespace std;
#define PB push_back
#define ZERO (1e-10)
#define INF int(1e9+1)
#define CL(A,I) (memset(A,I,sizeof(A)))
#define DEB printf("DEB!\n");
#define D(X) cout<<"  "<<#X": "<<X<<endl;
#define EQ(A,B) (A+ZERO>B&&A-ZERO<B)
typedef long long ll;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef pair<int,int> ii;
typedef vector<ii> vii;
#define IN(n) int n;scanf("%d",&n);
#define FOR(i, m, n) for (int i(m); i < n; i++)
#define F(n) FOR(i,0,n)
#define FF(n) FOR(j,0,n)
#define FT(m, n) FOR(k, m, n)
#define aa first
#define bb second
void ga(int N,int *A){F(N)scanf("%d",A+i);}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
struct TP{
    typedef int tp;
    tree<tp,null_type,less<tp>,rb_tree_tag,tree_order_statistics_node_update> T;
    void add(tp a){T.insert(a);} 
    void del(tp a){T.erase(a);}
    int cnt(tp a){return T.order_of_key(a);}
    tp kth(int a){return *T.find_by_order(a);}
    int gt(tp b,tp e){return cnt(e+1)-cnt(b);}
    int sz(){return T.size();}
    void clr(){T.clear();}
    int mn(){return kth(0);}
    int mx(){return kth(sz()-1);}
}T;
#define LG (18)
#define MX (1<<LG)
#define P2(v) (!(v&(v-1)))
struct RMQ{
    int dp[LG+2][MX],XX,O=-1,G[MX];
    void ini(int*A,int n){
        if(!XX++)FT(1,MX)G[k]=O+=P2(k);
        F(n)dp[0][i]=i;
        FT(1,k-(1<<k)+n+1)F(n+1-(1<<k))
            if(A[dp[k-1][i]]<A[dp[k-1][i+(1<<(k-1))]])
                dp[k][i]=dp[k-1][i];
            else dp[k][i]=dp[k-1][i+(1<<(k-1))];
    }
    int qy(int*A,int L,int R){
        const int j=G[R-L+1];
        if(A[dp[j][L]]<=A[dp[j][R-(1<<j)+1]])
            return A[dp[j][L]];
        return A[dp[j][R-(1<<j)+1]];
    }
}b;
struct RMQ2{
    int dp[MX][LG+2],G[MX],XX,O=-1;
    void ini(int*A,int n){
        if(!XX++)FT(1,MX)G[k]=O+=P2(k);
        F(n)dp[i][0]=i;
        FT(1,k-(1<<k)+n+1)F(n+1-(1<<k))
            if(A[dp[i][k-1]]>A[dp[i+(1<<(k-1))][k-1]])
                dp[i][k]=dp[i][k-1];
            else dp[i][k]=dp[i+(1<<(k-1))][k-1];      
    }
    int qy(int *A,int L,int R){
        int j(G[R-L+1]);
        if(A[dp[L][j]]>=A[dp[R-(1<<j)+1][j]])
            return A[dp[L][j]];
        return A[dp[R-(1<<j)+1][j]];
    }
}e;
int N,A[MX],X[MX][5],Y[MX][5];
int nrm(int a,int b,int c){
    int B[3]={a,b,c},L;
    sort(B,B+3),L=unique(B,B+3)-B;
    unordered_map<int,int> T;
    F(L)T[B[i]]=i+1;
    return 100*T[a]+10*T[b]+T[c];
}
void go(int X[MX][5]){
    T.clr();
    FT(1,N){
        T.add(A[k-1]);
        if(T.mn()<A[k])X[k][0]=T.mn();
        if(T.mx()>A[k])X[k][4]=T.mx();
        int I=T.cnt(A[k]);
        if(T.mx()>=A[k]&&T.kth(I)==A[k])X[k][2]=A[k];
        if(T.mn()<A[k])X[k][1]=T.kth(I-1);
        if(T.mx()>A[k])X[k][3]=~X[k][2]?T.kth(I+1):T.kth(I);
    }
}
set<int> O;
map<int,int> L;
int main(void){
    scanf("%d",&N),ga(N,A),CL(X,-1),CL(Y,-1),b.ini(A,N),e.ini(A,N);
    F(N){
        if(L.count(A[i])){
            if(b.qy(A,L[A[i]],i)<A[i])O.insert(212);
            if(e.qy(A,L[A[i]],i)>A[i])O.insert(121);
        }
        L[A[i]]=i;
    }
    go(X);
    reverse(A,A+N),go(Y);
    reverse(A,A+N);
    F(N/2)FF(5)swap(Y[i][j],Y[N-i-1][j]);
//    F(N){
//        DEB
//        printf("%d: ",A[i]);FF(5)printf(" %d",X[i][j]);puts("");
//        printf("%d: ",A[i]);FF(5)printf(" %d",Y[i][j]);puts("");
//    }
    F(N)FF(5)if(~X[i][j])FT(0,5)if(~Y[i][k])O.insert(nrm(X[i][j],A[i],Y[i][k]));
    for(auto&h:O)printf("%d\n",h);
    return 0;
}