import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import itertools

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

it = itertools.product(range(1,300), range(A+1), range(B+1))
answer = 'Impossible'
for p,a,b in it:
    # 1円、10円、購入額
    x = a + b * 10 - p
    if x < 0:
        continue
    n = (A-a) + (B-b) + (x//10) + (x%10)
    if n == C:
        answer = p
        break

print(answer)