import numpy as np
a,b,c=map(lambda x:int(x)*(10**18),input().split())
if a==b==0:
  if c:
    print(0)
  else:
    print(-1)
elif a==0:
  x=sorted(set(np.roots([b,c])))
  print(len(x))
  print(*x,sep='\n')
else:
  x=sorted(set(np.roots([a,b,c])))
  print(len(x))
  print(*x,sep='\n')