#!/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()