import math
N = int(input())
main = [list(map(int, input().split())) for _ in range(N)]   
ans = []
for i in range(N):
    for j in range(i+1,N):
        a,b = main[i]
        c,d = main[j]
        tmp = math.sqrt((a-c)**2 + (c-d)**2)
        ans.append(tmp)  
ans.sort(reverse=True)

def is_ok(mid):
    if ans[0]-mid <0:
        ok = False
    else:
        ok = True
    return ok


def binary_search(ok, ng):
    """二分探索

    Parameters
    ----------
    ok : int
    ng : int

    Returns
    -------
    ok : int
    """
    while ng - ok > 1:
        mid = (ok + ng) // 2
        
        if is_ok(mid):
            ok = mid
        else:
            ng = mid
    return ok

ans1 = binary_search(0, 10**9+1)
q, mod = divmod(ans1,10)
if mod == 0:
    ans1 = q * 10
else:
    ans1 = (q+1) * 10
print(ans1)