A, B, C = map(int, input().split())
n = A + B - C
if n > 0:
    if n < 10 and n <= A:
        print(n)
    elif n < 10 and n > A:
        print(A+(n-A)*10)
    elif n >= 10 :
        n1 = n + n//10
        if n1 <= A:
            print(n1 - n1//10*10)
        else:
            print(A + (n-A)*10)
elif n < 0:
    if B == 0:
        print("Impossible")
    elif n > -9:
        print(10 + n -1)
    else:
        print("Impossible")    
else:
    print("Impossible")