macro_rules! read_line_to_tuple {
    ( $( $t:ty ),* ) => {{
        let mut input = String::new();
        std::io::stdin().read_line(&mut input).unwrap();
        let mut iter = input.split_whitespace();
        ( $( iter.next().unwrap().parse::<$t>().unwrap() ),* )
    }};
}

macro_rules! read_line_to_collection {
    ( $t:ty ) => {{
        let mut input = String::new();
        std::io::stdin().read_line(&mut input).unwrap();
        let iter = input.split_whitespace();
        iter.map(|x| x.parse().unwrap()).collect::<$t>()
    }};
}

const MOD: i64 = 1_000_000_007;

fn main() {
    let n = read_line_to_tuple!(usize);
    let a = read_line_to_collection!(Vec<i64>);

    let min = *a.iter().min().unwrap();
    if min == 0 {
        return println!("-1");
    }

    let max = *a.iter().max().unwrap();
    if max >= 4 {
        return println!("{}", MOD);
    }

    let pow = |mut a: i64, mut n: usize| -> i64 {
        let mut res = 1;
        while n > 0 {
            if n & 1 > 0 {
                res = res * a % MOD;
            }
            a = a * a % MOD;
            n >>= 1;
        }
        res
    };

    let mut ans = 1;
    for i in 0..n {
        let k = (1..=a[i]).fold(1, |acc, x| acc * x);
        ans = ans * pow(a[i], k as usize);
        if ans > MOD {
            return println!("{}", MOD);
        }
    }
    println!("{}", MOD % ans);
}