A,B,C=map(int,input().split())

def rest(i,j,money):
    otsuri=i+10*j-money

    return otsuri//10+otsuri%10

ANS=[]
for i in range(A+1):
    for j in range(B+1):
        if i+j==0:
            continue

        for money in range(1,i+10*B+1):
            otsuri=rest(i,j,money)
            if otsuri+(A-i)+(B-j)==C:
                ANS.append(money)


if len(ANS)>0:
    print(min(ANS))
else:
    print("Impossible")