from sys import argv, exit
import re
if len(argv) < 2:
    print("mising command-line argument")
    exit(1)

with open(argv[1], "r") as f:
    count = 0
    contents = f.read()
    print(contents)
    print(contents[0:4])
    i = 0
    j = i + 4
    while contents[i:j]: # will read contents until end of file
        span = contents[i:j] # span will be a substring of contents from i to j
        while contents[i+4:j+4] == span: # while the next 4 indices have the same values of the index span
            count += 1
            i += 4
            j += 4
        i += 4
        j += 4
        print("span " + span + " repeats " + str(count) + " times" )