Help with small program

[smartbei]

Hello, I am a newbie with python, though I am having a lot of fun using
it. Here is one of the excersizes I am trying to complete:
the program is supposed to find the coin combination so that with 10
coins you can reach a certain amoung, taken as a parameter. Here is the
current program:

coins = (100,10,5,1,0.5)
anslist = []
def bar(fin, hist = {100:0,10:0,5:0,1:0,0.5:0}):
	s = sum(x*hist[x] for x in hist)
	l = sum(hist.values())
	if s < fin and l < 10:
		for c in coins:
			if (s+c) <= fin:
				hist[c] += 1
				bar(fin, hist)
				hist[c] -= 1
	elif l==10 and s==fin and not hist in anslist:
		#p1
		anslist.append(hist)

bar(50)
print anslist

The problem is that if I run it, anslist prints as [{0.5: 0, 1: 0, 10:
0, 100: 0, 5: 0}], which doesnt even add up to 50. When I check how
many times the program has reached the #p1 by sticking a print there,
it only reaches it once, and it comes out correct. why is it that this
result is replaced by the incorrect final one?