def func(n1:int,n10:int,r:int):
    a,b =n1,n10
    if n1 + n10 <= r:
        return "Impossible"
    else:
        p1,p10 =0,0
        while n1+n10-r >0:
            if n1>0:
                n1 -= 1
                p1 += 1
            else:
                if n10>0:
                    n10 -= 1
                    p10 += 1
    #釣りを受け取れる場合
    while n1 > 1 and p1 > 10:
        n1 -=1
        p1 +=1
        p1 -=10
        n10 +=1
    ans = a+b*10 - (n1 + n10 *10)
    return ans

a,b,c = map(int,input().split())
print(func(a,b,c))