#include <iostream>

int main () {
    int n;
    std::cin >> n;
    int a[n];
    for (int i = 0;i<n;i++) {
        int p ;
        std::cin >> p;
        a[i] = p;
    }
    int temp = 0;
    for (int i = n-2;i>=0;i--) {
        if (a[i] != a[n-1]) temp++;
    }
    int pepa = 0;
    if (temp%2 ==0) {
        for (int i = 0;i<n-1;i++) {
            if (a[i]!=a[n-1]) pepa += a[i];
        }
        std::cout << pepa;
        return 0;
    }
    else {
            pepa = 1;
            for (int i = 0;i<n;i++) {
                if (a[i] != a[n-1]) pepa *=a[i];
            }
            std::cout << pepa;
            return 0;
    }
}