# L-31 MCS 260 Wed 7 Nov 2007 : dyneval.py
#
# Thanks to Python's dynamic typing,
# expressions may be evaluated dynamically
# as well, via the "eval" command.
# Any valid Python expression the user
# enters will be evaluated at the given x.

from math import *
e = raw_input('f(x) = ')
x = input('x = ')
y = eval(e)
print e + ' at x = ' + str(x)
print 'equals ' + str(y)