a,b,c = map(int,input().split())
ans = 1e9
s = a + b*10
def calc(x):
    return x//10 + x%10
for price in range(1,s+1):
    for pay in range(price,s+1):
        for c10 in range(b+1):
            if c10*10 > pay or pay - c10*10 > a:
                continue
            if b-c10 + a-(pay - c10*10) + calc(pay-price) == c:
                ans = min(ans, price)
if ans == 1e9:
    ans = "Impossible"
print(ans)