n=int(input())
points = []
for _ in range(n):
    x, y = map(int, input().split())
    points.append((x,y))

# sorted(points, key=lambda p: p[0])
points = sorted(points)
# print(points)

x_dist = abs(points[0][0] - points[-1][0])
y_dist = 0
for i in range(len(points) - 1):
    y_dist += abs(points[i][1] - points[i+1][1]) 
print(x_dist + y_dist)