a,b,c=map(int,raw_input().split())

if a!=0:
    d=b**2-4*a*c
    if d<0:
        print -1
    elif d==0:
        print 1
        print -b/(2.0*a)
    else:
        print 2
        print (-b-(d)**0.5)/(2.0*a)
        print (-b+(d)**0.5)/(2.0*a)
else:
    if b==0:
        print -1
    else:
        print -c/(b*1.0)
