def parseFile(filename):
    file = open(filename)
    for line in f:
        #reg helps parse file
        #\s matches single whitespace character
        #\d matches digit
        reg = re.match( r'(\d+)\s(\d+)', str(line))
        #all matching subgroups in a tuple
        i = int(reg.group(1))
        j = int(reg.group(2))
        #Containers for the graph, graphReverse
        g = []
        gR = []
        while(len(g) < i):
            g.append([])
        g[i-1].append(j)

        while(len(gR) < j):
            gR.append([])
        gR[j-1].append(i)