#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using PI = pair<int,int>;


int main() {
    // #ifndef ONLINE_JUDGE
    // freopen("input.txt", "r", stdin);
    // #endif
    
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int t;
    //cin>>t;
    t = 1;
    while(t--) {
        int n, a, b;
        cin>>n>>a>>b;

        vector<int> dancers(n);
        for(auto &v: dancers) {
            cin>>v;
        }

        int invalid = 0, ret = 0;
        for(int i = 0; i < n / 2; i++) {
            int left = dancers[i], right = dancers[n-1-i];
            
            if (left == right) {
                if(left == 2) ret += 2*min(a, b);
                continue;
            }

            if(left < 2 && right < 2) {
                invalid = 1;
                break;
            }

            if(left == 2) {
                if(right == 0) ret += a;
                else ret += b;
                continue;
            }

            if(right == 2) {
                if(left == 0) ret += a;
                else ret += b;
                continue;
            }
        }

        if (n%2 == 1 && dancers[n/2] == 2) ret += min(a,b);

        if (invalid) cout<<-1<<endl;
        else cout<<ret<<endl;


    }

    return 0;
}