#include <iostream>
using namespace std;

int main() {
    int n;
    while (cin >> n) cout << n * n << endl;
    return  0 ;
}

from os import popen2

z = popen2('E:/zzz.exe')

test_in = \
"""
1
2
3
4
5
"""

test_out = \
"""1
4
9
16
25
"""


z[ 0 ].write(test_in)
z[ 0 ].close()

ans = z[ 1 ].read()
z[ 1 ].close()

print ans

if ans == test_out:
    print 'Accepted'
else:
    print 'Wrong Answer'

>>> 
 1 
 4 
 9 
 16 
 25 

Accepted
>>>

tested_file = 'E:/zzz.exe'
test_data_in = '1 2 3 4 5'
test_data_out = '1 4 9 16 25 '
time_limit =  1 
exe_ans = None

import os
from time import time, sleep

start_time = time()

exe_stdin, exe_stdout = os.popen2(tested_file)
exe_stdin.write(test_data_in)
exe_stdin.close()

def exe_stdout_read():
    global exe_ans
    exe_ans = exe_stdout.read()
    exe_stdout.close()

import thread
thread.start_new_thread(exe_stdout_read, ())

while not(exe_stdout.closed) and time() - start_time < time_limit *  1 . 1 :
    sleep( 0 . 005 )

delta_time = time() - start_time

if not(exe_stdout.closed):
    os.system('pskill ' + tested_file[ 1  + tested_file.rfind('/'):])

print 'Time:', delta_time

if delta_time > time_limit:
    print 'Time Limit Exceeded'
elif exe_ans == test_data_out:
    print 'Accepted'
else:
    print 'Wrong Answer'