def dist(l, r):
    lx, ly = l
    rx, ry = r

    return abs(lx-rx) + abs(ly-ry)

inputs = int(input())

points = []

for _ in range(inputs):
    line = input().split(' ')
    x, y = int(line[0]), int(line[1])
    points.append((x, y))

points.sort()

total = 0

for i in range(inputs-1):
    current = points[i]
    n = points[i+1]
    total += dist(current, n)

print(total)