fn main() {
    let n = {
        let mut line = String::new();
        std::io::stdin().read_line(&mut line).unwrap();
        line.trim().parse::<usize>().unwrap()
    };
    let _m1 = {
        let mut line = String::new();
        std::io::stdin().read_line(&mut line).unwrap();
        line.trim().parse::<usize>().unwrap()
    };
    let aa: Vec<_> = {
        let mut line = String::new();
        std::io::stdin().read_line(&mut line).unwrap();
        line.split_whitespace()
            .map(|x| x.parse::<usize>().unwrap())
            .collect()
    };
    let _m2 = {
        let mut line = String::new();
        std::io::stdin().read_line(&mut line).unwrap();
        line.trim().parse::<usize>().unwrap()
    };
    let bb: Vec<_> = {
        let mut line = String::new();
        std::io::stdin().read_line(&mut line).unwrap();
        line.split_whitespace()
            .map(|x| x.parse::<usize>().unwrap())
            .collect()
    };

    let mut visited = vec![false; n + 1];
    let mut cur = 0;
    for &a in &aa {
        cur += a;
        visited[cur] = true;
    }
    for &b in &bb {
        cur -= b;
        visited[cur] = true;
    }

    let ans = visited.iter().filter(|&&x| !x).count();
    println!("{}", ans);
}