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

m = A + B*10
f = False

for a in range(A + 1):
  for b in range(B + 1):
    for x in range(1, a + b*10 + 1):
      o = (a + b*10) - x
      tmp = A + B - (a + b) + (o // 10 + o % 10)
      if tmp == C:
        f = True
        m = min(m, x)
        #print('A:{} B:{} C:{} a:{} b:{} x:{} o:{} tmp:{} m:{}'.format(A, B, C, a, b, x, o, tmp, m))

print(['Impossible',m][f])