#yuki825

a,b,c=map(int,raw_input().split())
res=a+b*10+2
for i in xrange(a+b*10+1):
 for j in xrange(b+a/10+1):
  if i+j==c and i+j*10<=a+b*10 and i-a<10:
   res=min(res,a-i+(b-j)*10)
if res>a+b*10 or res<=0:
 print 'Impossible'
else:
 print res