#include<cstdio>
#include<algorithm>
using namespace std;
using ll = long long;
using ull = unsigned long long;

int main(){
    int N;
    scanf("%d", &N);
    if(N > 1 && (N&1)){
        printf("1\n");
        return 0;
    }
    int A[N];
    for(int i = 0; i < N; ++i) scanf("%d", A + i);
    if(N == 1) printf("%d\n", A[0]);
    else if(N == 2) printf("%d\n", A[0]*A[1]);
    else{
        nth_element(A,A+2,A+N);
        printf("%d\n", A[0] >= 1000000000/A[1] ? A[2] : min(A[0]*A[1], A[2]));
    }
    return 0;
}