use std::io::Read;
use std::collections::HashSet;

fn solve(n: usize, a: Vec<usize>) {
    let summary: usize = a.iter().sum();
    let divisors = get_divisors(summary);
    for d in divisors {
        if d > n {
            continue;
        }
        let avg: usize = summary / d;
        let mut flg = true;
        let mut temp = 0;
        for v in a.iter() {
            temp += v;
            if temp > avg {
                flg = false;
                break;
            }
            if temp == avg {
                temp = 0;
            }
        }
        if flg {
            println!("{}", d);
            return;
        }
    }
    println!("{}", -1);
}

fn get_divisors(target: usize) -> Vec<usize> {
    let mut divisors: HashSet<usize> = HashSet::new();
    let iter_limit = (((target + 1) as f64).powf(0.5)) as usize;
    for i in 1..=iter_limit {
        if target % i == 0 {
            divisors.insert(i);
            divisors.insert(target / i);
        }
    }
    let mut divisors: Vec<usize> = divisors.iter().map(|d| *d).collect();
    divisors.sort();
    divisors.iter().rev().map(|d| *d).collect()
}

fn main() {
    let mut na = String::new();
    std::io::stdin().read_to_string(&mut na).ok();
    let na: Vec<&str> = na.trim().split('\n').take(2)
        .map(|s| s.trim())
        .collect();
    let n: usize = na[0].parse::<usize>().unwrap();
    let a: Vec<usize> = na[1].split_whitespace().map(|s| s.parse::<usize>().unwrap()).collect();
    solve(n, a);
}