#ICAMPSEQ. IOICamp Sequence

IOICamp Sequence

Let's say we have 4 N-elements sequences of real numbers: A[], B[], C[], D[] .
Funtion F(i, j) is defined: F(i, j) = |Ai - Aj| + |Bi - Bj| + |Ci - Cj| + |Di - Dj| (1 ≤ i, j ≤ N).
Your task is very easy: you have to find the maximum of F(i, j).

Input

The first line: N (N ≤ 100000).
Following are N lines: the i-th line contains four real numbers Ai, Bi, Ci, Di. (-109 ≤ Ai, Bi, Ci, Di ≤ 109)

Output

Only one line is the maximum of F(i, j).
(The result takes exactly 3 decimal places)

Example

Input:
2
1.0 1.0 2.0 0.5
1.0 1.0 0.5 2.0


Output:
3.000