n, a, b = map(int, input().split())
l = list(map(int, input().split()))
sum = 0
costs = {0: a, 1: b}
for i in range(len(l) // 2 if len(l) % 2 == 0 else (len(l) // 2) + 1):
if l[i] == l[-(i+1)] and l[i] != 2:
continue
elif l[i] == l[-(i+1)] and l[i] == 2 and ( i == len(l) - (i+1) ):
sum += min(a, b)
elif l[i] == l[-(i+1)] and l[i] == 2:
sum += 2*min(a, b)
elif l[i] == 2 or l[-(i+1)] == 2:
if l[i] == 2:
sum += costs[l[-(i+1)]]
else:
sum += costs[l[i]]
else:
print(-1)
exit()
print(sum)/** Read statement carefully **/
#include <bits/stdc++.h>
using namespace std;
#define debug(x) cout<< #x << " = " << x <<endl;
#define ll long long
#define yes cout<< "Yes" << "\n"
#define no cout<< "No" << "\n"
#define eps 1e-7
#define pb push_back
#define F first
#define S second
#define endl "\n"
const int sz = 2e5 + 5;
const int N = 1e5 + 5;
const int mod = 1e9 + 7;
const ll Inf = 1e18;
ll dr[] = {-1, +1, 0, 0};
ll dc[] = { 0, 0, +1, -1};
void solve() {
ll n, aa, bb; cin>> n >> aa >> bb;
ll ara[n];
for(ll i = 0; i <n; i ++) cin>> ara[i];
ll ans = 0;
if(n % 2) {
if(ara[n / 2] == 2) {
ans = min(aa, bb);
}
}
for(ll i = 0; i < n / 2; i ++) {
if(ara[i] == ara[n - i - 1]) {
if(ara[i] == 2)
ans += 2 * min(aa, bb);
}
else {
if((ara[i] ^ ara[n - i - 1]) == 1) {
cout<< -1 << endl; return;
}
else {
ll a;
if(ara[i] == 2) a = ara[n - i - 1];
else a = ara[i];
if(a == 0) ans += aa;
else ans += bb;
}
}
}
cout<< ans << endl;
}
int32_t main()
{
ios::sync_with_stdio(false);cin.tie(0);
ll T; T = 1;
// cin >> T;
while(T --) {
solve();
}
return 0;
}
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