#include<iostream>
#include<cstdio>
#define NUM 510
#define int long long
#define FOR(a,b,c) for( int a = b;a <= c;a++ )
using namespace std;

int n;
int a[NUM];
long long dp[NUM][NUM];

signed main(){
    
    cin >> n;
    FOR( i,1,n ){
        cin >> a[i];
        a[i+n] = a[i];
    }
    
    FOR( len,2,n+2 ){ //枚舉區間長度(n+1)
        FOR( l,1,n*2-len+1 ){ //( 循環條件改了，原來是枚舉到n )
            int r = l+len-1;
            
//          if( len == 2 ){ //( 刪除掉！ )
//              dp[l][r] = a[l]*a[r]*a[r+1];
//              printf( "區間為%d-%d，dp = %d\n",l,r,dp[l][r] );
//              continue;
//         }
            FOR( t,l+1,r-1 ){
                dp[l][r] = max( dp[l][r],dp[l][t]+dp[t][r]+a[l]*a[t]*a[r] );//(*a[t]*a[r])
            }
//          printf( "區間為%d-%d，dp = %d\n",l,r,dp[l][r] );
        }
    }
    long long ans = 0;
    FOR( i,1,n ){
        ans = max( ans,dp[i][i+n] );//( [i+n] )
    }
    cout << ans;
    
    return 0;
}