# L-15 MCS 260 Mon 1 Oct 2007 : eval()
#
# With eval() we can turn expressions
# into functions.

def make_fun():
   s = raw_input('give an expression : ')
   x = raw_input('give the variable name : ')
   f = lambda x : eval(s)
   return f

g = make_fun()
v = input('give a value : ')
y = g(v)
print 'the expression evaluated at %f' % v
print 'gives %f ' % y