A,B,C = map(int,input().split())
inf = 1 << 60
ans = inf
for a in range(A+1):
    for b in range(B+1):
        for i in range(1,221):
            if a+b*10 >= i:
                change = a+b*10 - i
                n = (A-a)+(B-b)+(change//10)+(change%10)
                if n == C:
                    ans = min(ans, i)
if ans == inf:
    print('Impossible')
else:
    print(ans)