#!/usr/bin/python

import sys

if len(sys.argv) < 3:
    sys.stderr.write("usage: icom FILE1 FILE2\n")
    sys.exit(1)

tsz = (25, 25)

files = []

for i in xrange(2):
    f = open(sys.argv[i + 1])
    lines = []
    for y in xrange(tsz[1]):
        line = []
        for x in xrange(tsz[0]):
            p = []
            for c in f.read(3):
                p.append(ord(c))
            line.append(tuple(p))
        lines.append(line)
    files.append(lines)
    f.close()

sum = 0

for y in xrange(tsz[1]):
    for x in xrange(tsz[0]):
        p = [f[y][x] for f in files]
        for c in xrange(2):
            sum += abs(p[0][c] - p[1][c])

print sum