"""
stack usage: check delimiter matching
"""
from stack import Stack
import sys
#equation = 'a=b+(c-d)*(e-f))'
equation = sys.argv[1]
s = Stack()
for _ in equation:
if '(' == _:
s.push(_)
elif ')' == _:
if '(' == s.topEl():
s.top()
else:
s.push(_)
if s.isEmpty():
print 'match equation\n'
else:
print 'mismatch equation\n'
