//https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8 より
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}

// ここまで

fn gcd(mut a: i64, mut b: i64) -> i64 {
    if a == 0 || b == 0 {
        return a + b;
    }
    let mut r = a % b;
    while r > 0 {
        a = b;
        b = r;
        r = a % b;
    }
    b
}

fn run() {
    input! {
        n: usize,
        p: [(i64, i64); n],
    }
    let p: Vec<(i64, i64)> = p.into_iter().filter(|p| !(p.0 == 0 && p.1 == 0)).collect();
    let n = p.len();
    let mut ans = 0.0;
    for i in 0..n {
        {
            let (x, y) = p[i];
            let v = ((x * x + y * y) as f64).sqrt();
            if v > ans {
                ans = v;
            }
        }
        for j in 0..n {
            if i == j {
                continue;
            }
            let (a, b) = p[i];
            let (c, d) = p[j];
            let mut x = 1.0;
            let mut y = 1.0;
            if a * d - b * c != 0 {
                let det = (a * d - b * c) as f64;
                for k in 0..n {
                    if k == i || k == j {
                        continue;
                    }
                    let (e, f) = p[k];
                    let z = ( d * e - c * f) as f64 / det;
                    let w = (-b * e + a * f) as f64 / det;
                    if z + w > 0.0 {
                        x += z;
                        y += w;
                    }
                }
            } else {
                let g = gcd(a.abs(), b.abs());
                let (a, b) = (a / g, b / g);
                y = 0.0;
                for k in 0..n {
                    if k == i {
                        continue;
                    }
                    let (e, f) = p[k];
                    if (a != 0 && (e / a) * b == f) || (b != 0 && (f / b) * a == e) {
                        let k = if a != 0 {e / a} else {f / b} as f64 / g as f64;
                        if k > 0.0 {
                            x += k;
                        }
                    }
                }
            }
            let dx = a as f64 * x + c as f64 * y;
            let dy = b as f64 * x + d as f64 * y;
            let l = (dx * dx + dy * dy).sqrt();
            if l > ans {
                ans = l;
            }
        }
    }
    println!("{:.11}", ans);
}

fn main() {
    run();
}


Measured memory_bytes: 4476