4
1 4 3 2

1 2

 1
 
 #include <cstdio>
 2 #include <iostream>
 3 #include <cstring>
 4 #define N 157
 5 #define rep(i,a,b) for(int i=a;i<=b;i++)
 6 using namespace std;
 7 bool f[N][N][8];
 8 int n,a[N];
 9 
10 void Init(){
11     scanf("%d",&n);
12     rep(i,1,n)    scanf("%d",&a[i]);
13 }
 
14 
15 void Work(){
16     rep(i,1,n) f[i][i][a[i]]=1;
17     
18     for(int i=n;i>=1;i--)
19         rep(j,i+1,n)
20             rep(k,i,j)    
21                 rep(x,0,7)
22                     rep(y,0,7)
23                         f[i][j][(x+y)/2]=f[i][j][(x+y)/2] | (f[i][k][x]&f[k+1][j][y]);
24 
25     rep(i,0,7)
26         if (f[1][n][i])    printf("%d ",i);
27 }
28 
29 int main(){
30     freopen("math.in","r",stdin);
31     freopen("math.out","w",stdout);
32     Init();
33     Work();
34 }