from heapq import heappush, heappop
import math


def d2(p1, p2):
    return (p1[0] - p2[0]) ** 2 + (p1[1] - p2[1]) ** 2


def dij(n, ps):
    start = 0
    goal = n - 1

    d2mat = [[0] * n for i in range(n)]

    pset = set(range(n))

    for i in range(n):
        for j in range(i + 1, n):
            d2mat[i][j] = d2mat[j][i] = d2(ps[i], ps[j])

    d = [d2mat[start][i] for i in range(n)]

    hq = []
    for i in range(n):
        heappush(hq, (d[i], i))

    while hq:
        m, i = heappop(hq)

        if d[i] < m:
            continue

        if i == goal:
            return m

        pset.remove(i)

        for j in pset:
            dij = d2mat[i][j]
            mj = max(m, dij)
            if d[j] > mj:
                d[j] = mj
                heappush(hq, (mj, j))
    return d[goal]


def solve(n, ps):
    ans = dij(n, ps)
    a2 = math.sqrt(ans)
    c = math.ceil(a2 / 10)

    return min(filter(lambda a: (a * 10) ** 2 >= ans, [c - 1, c, c + 1])) * 10


def main():
    n = int(input())
    ps = []
    for i in range(n):
        x, y = list(map(int, input().split()))
        ps.append((x, y))
    print(solve(n, ps))


if __name__ == '__main__':
    main()