a,b,c=map(int, raw_input().split())
chk=b**2-4*a*c
ans=[]

if chk<0:
    print 0
    exit()
elif a!=0:
    print 'u'
    ans.append(((-1.0*b)+(chk**0.5))/(2*a))
    ans.append(((-1.0*b)-(chk**0.5))/(2*a))
else:
    if b!=0:
        ans.append((-1.0*c)/b)
    elif c!=0:
        ans.append(-1.0*c)
ans.sort()
if a==b==c==0:
    print -1
elif a==b==0:
    print 0
else:
#elif len(ans):
    print len(ans)
    for i in ans:
        print i