import itertools

def yoba(c, n, g):
	all_combinations = itertools.combinations_with_replacement(c, n)
	combinations = itertools.ifilter(lambda x: sum(x) == g, all_combinations)
	return next(combinations, None)
	
c = [1, 2, 5, 10, 25]
g = 30


print yoba(c, 4, g)
print yoba(c, 1, g)