import math


def dist2(p1, p2):
    return (p1[0] - p2[0]) ** 2 + (p1[1] - p2[1]) ** 2

def md(ds, g):
    g = list(g)

    m = 0
    for i in range(len(g)):
        for j in range(i + 1, len(g)):
            d2 = ds[g[i]][g[j]]
            if d2 > m:
                m = d2
    return m


def solve(n, ps):
    ds = [[0] * n for i in range(n)]

    for i in range(n):
        pi = ps[i]
        for j in range(i + 1, n):
            pj = ps[j]
            d2 = dist2(pi, pj)
            ds[i][j] = ds[j][i] = d2

    g = [None] * n
    gs = []

    # 相互通信できるグループに分ける
    for i in range(n):
        if g[i] is not None:
            continue
        g[i] = {i}
        gs.append(g[i])
        stack = [i]
        while stack:
            j = stack.pop()
            for k in range(n):
                if g[k] is not None:
                    continue
                if ds[j][k] > 100:
                    continue
                g[k] = g[j]
                g[k].add(k)
                stack.append(k)

    # グループ内のアンテナの間の最大距離をグループごとに求める
    # それの最大値 + 2 が答え
    if len(gs) < 1:
        return 1
    mmd = math.sqrt(max(md(ds, g) for g in gs))
    return mmd + 2


def main():
    n = int(input())
    ps = []
    for i in range(n):
        ps.append(tuple(map(int, input().split())))

    a = solve(n, ps)
    print(a)


if __name__ == '__main__':
    main()