def scalar(a, b):
    return a[0] * b[0] + a[1] * b[1]

def get_sq(a, b):
    return (a[0]**2 + a[1]**2) ** 0.5 * (b[0]**2 + b[1]**2) ** 0.5 

def main():
    n = int(input())
    points = []
    sq = -1
    for i in range(n):
        point = list(map(int, input().split()))
        points.append(point)
    for i in range(n):
        for j in range(i + 1, n):
            for k in range(j + 1, n):
                a = [points[i][0] - points[j][0], points[i][1] - points[j][1]]
                b = [points[i][0] - points[k][0], points[i][1] - points[k][1]]
                if scalar(a, b) == 0:
                    if sq == -1:
                        sq = get_sq(a, b)
                    sq = min(sq, get_sq(a, b))
    print(int(sq))
    

main()