A, B, C = map(int, raw_input().split())
min = -1
for i in range(0, A+1):
	for j in range(0, B+1):
		maxprice = i+10*j
		for k in range(1, maxprice+1):
			change1 = (maxprice-k)%10
			change10 = (maxprice-k)/10
			coins = A-i + B-j + change1 + change10
			if coins == C:
				if k < min or min == -1: min = k
if min == -1: print 'Impossible'
else: print min