a,b,c = map(int,input().split())
for i in range(1, a+b*10+1):
    for j in range(a+1):
        for k in range(b+1):
            p = j+k*10
            if p < i:
                continue
            t = p-i
            r = a-j+t%10 + b-k+t//10
            if r == c:
                print(i)
                exit(0)
print('Impossible')