#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);}
#define MX 222222
struct STOP{
    clock_t S;
    void ini(){S=clock();}
    bool ok(double Z){return (clock()-S)/(double)CLOCKS_PER_SEC<Z;};
}T;
void rnm(int*A,int N){
    static ii B[MX];
    int L=0;
    F(N)B[i]={A[i],i};
    sort(B,B+N);
    F(N)A[B[i].bb]=L+=i&&B[i].aa^B[i-1].aa;
}
int N,A[MX],W[MX];
vi F[MX],P;
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;
    F(L)W[B[i]]=i+1;
    return 100*W[a]+10*W[b]+W[c];
}
int O[666];
int main(void){
    scanf("%d",&N),ga(N,A),T.ini(),rnm(A,N);
    F(N){
        F[A[i]].PB(i);
        if(F[A[i]].size()>2u)O[111]=1;
    }
    F(N)if(F[i].size()>1u)P.PB(i);
    if(!P.empty())F(333){
        int I=P[rand()%P.size()],a=F[I][0],b=F[I].back();
        FT(a+1,b)O[nrm(A[a],A[k],A[b])]=1;
    }
    while(T.ok(2)){
        int a=rand()%N,b=rand()%N,c=rand()%N;
        if(a==b||a==c||b==c)continue;
        if(a>b)swap(a,b);
        if(a>c)swap(a,c);
        if(b>c)swap(b,c);
        O[nrm(A[a],A[b],A[c])]=1;
    }
    F(666)if(O[i])printf("%d\n",i);
    return 0;
}