def fx(A,B,C):
    # if A+B==C:  return 0
    M=A+B*10
    for i in range(1,M+1):
        a,b=(M-i)%10,(M-i)//10
        if a+b==C:  return i
    return "Impossible"

def main():
    A,B,C=[int(s) for s in input().split()]
    n=fx(A,B,C)
    print(n)

main()