8115

#include <stdio.h>

int main(void) {
    int n, min, minp, i, j;
    min = 1000; minp = 1000*1000;
    scanf("%d", &n);

    int arr[7];

    for(i = 0; i < 6; i++)
        scanf("%d", &arr[i]);
    for(i = 6; i < n; i++) {
        scanf("%d", &arr[6]);
        if(arr[0] % 2 != 0 && arr[0] < min)
            min = arr[0];
        if(min * arr[6] < minp && min * arr[6] % 2 != 0)
            minp = min * arr[6];
        for(j = 0; j < 6; j++)
            arr[j] = arr[j+1];
    }
    if(minp % 2 == 0)
        printf("%d\n", -1);
    else
        printf("%d\n", minp);

    return 0;
}