#!/usr/bin/env python


def read_input():
    result = []
    with open('input.txt', 'r') as f:
        for line in f:
            result.append([ int(x) for x in line.split(', ')])
    return result

MARGIN=1
coord = read_input()
coord_min = [ min([x[0] for x in coord]), min([x[1] for x in coord]) ]
coord_max = [ max([x[0] for x in coord]), max([x[1] for x in coord]) ]

finite = [True] * len(coord)
area_size = [0] * len(coord)


for x in range(coord_min[0]-MARGIN, coord_max[0]+MARGIN+1):
    for y in range(coord_min[1]-MARGIN, coord_max[1]+MARGIN+1):
       border_x = False
       border_y = False
       if x in (coord_min[0]-MARGIN, coord_max[0]+MARGIN):
           border_x = True
       if y in (coord_min[1]-MARGIN, coord_max[1]+MARGIN):
           border_y = True

       best = (None, None) #loc, distance
       for loc_i, loc in  enumerate(coord):
           d = abs(x - loc[0]) + abs(y - loc[1])
           if best[1] is None:
               best = (loc_i, d)
               continue
           if best[1] > d:
               best = (loc_i, d)
               continue
           if best[1] == d:
               best = (None, d)
               continue

       if best[0] is None:
           continue

       if border_x or border_y:
           finite[best[0]] = False
       area_size[best[0]] += 1


print(max([v for k,v in enumerate(area_size) if finite[k]]))