import sys
import json
# load input arguments from the text file
filename = sys.argv[ 1 ]
with open( filename ) as data_file:
input_args = json.loads( data_file.read() )
# cast strings to floats
x, y = [ float(input_args.get( key )) for key in [ 'x', 'y' ] ]
print json.dumps( { 'sum' : x + y , 'subtract' : x - y } )