#!/usr/bin/env python
# PARENT
import subprocess
import sys

test = "./child.py"
process = subprocess.Popen(test, shell=True,
                           stdin=subprocess.PIPE, stdout=subprocess.PIPE)
for i in range(1000):
    process.stdin.write("%d\n" % (i,))
    process.stdin.flush()
    output = process.stdout.readline()
    print "OUTPUT =", output.strip()

process.stdin.close()
process.wait()



#!/usr/bin/env python
# CHILD
import sys

while True:
    line = sys.stdin.readline()
    if not line:
        break
    number = int(line)
    sys.stdout.write("%d\n" % (number ** 2,))
    sys.stdout.flush()