func main()
	var a: int :: cui@inputInt()
	var b: int :: cui@inputInt()
	var c: int :: cui@inputInt()
	var ans: int :: 10 ^ 10
	for aa(0, a)
		for bb(0, b)
			if(aa + bb = 0)
				skip bb
			end if
			for x(1, 220)
				var change: int :: 10 * bb + aa - x
				if(change < 0)
					skip x
				end if
				var cc: int :: change / 10 + change % 10
				if(a + b - aa - bb + cc = c)
					do ans :: [ans, x].min()
				end if
			end for
		end for
	end for
	if(ans = 10 ^ 10)
		do cui@print("Impossible\n")
	else
		do cui@print("\{ans}\n")
	end if
end func