Ускорение работы программы

import time
t1 = time.clock()
mas = []
mas1 = []
mas2 = []
with open('input.txt', 'r') as inp:
    n = int(inp.readline().strip())
    for i in range(n):
        mas1.append(inp.readline().strip())
    m = int(inp.readline().strip())
    print (mas1)
    for i in inp:
        print (i)
       if i in mas1:
            mas.append(i.strip())
            print ('blo')
        else:
            mas2.append(i.strip())
with open('output.txt', 'w') as out:
    out.write('Friends:')
    for i in range(n-2):
        out.write(' '+mas1[i]+',')
    out.write(' '+mas1[i+1]+'\n')
    out.write('Mutual Friends:')
    for i in range(len(mas)):
        out.write(' '+mas[i]+',')
    out.write ('\n')
    out.write('Also friend of:')
    for i in range(len(mas2)-1):
        out.write(' '+mas2[i]+',')
    out.write(' '+mas2[i+1])
print (mas1)
print (mas)
print (mas2)
print (time.clock()-t1)

with open('input.txt', 'r') as inp:
    file_list = inp.read().split()
list_1 = file_list[1:int(file_list[0])+1]
list_3 = file_list[int(file_list[0])+2:int(file_list[0])+2+int(file_list[int(file_list[0])+1])]
list_2 = list(set(list_1).intersection(set(list_3)))
list_1.sort()
list_2.sort()
list_3.sort()
for i in range(len(list_2)):
    if list_2[i] in list_3:
        list_3.remove(list_2[i])
with open('output.txt', 'w') as out:
    out.write('Friends:')
    if len(list_1) != 0:
        for i in range(int(file_list[0])-1):
            out.write(' '+list_1[i]+',')
        out.write(' '+list_1[-1]+'\n')
    else: out.write('\n')
    out.write('Mutual Friends:')
    if len(list_2) != 0:
        for i in range(len(list_2)-1):
            out.write(' '+list_2[i]+',')
        out.write(' '+list_2[-1]+'\n')
    else: out.write('\n')
    out.write('Also Friend of:')
    if len(list_1) != 0:
        for i in range(len(list_3)-1):
            out.write(' '+list_3[i]+',')
        out.write(' '+list_3[-1])

file_list = inp.readlines()