a,b,c=map(int,raw_input().split())
if a==b==c==0:
    print -1
elif a==b==0:
    print 0
elif a==0:
    print '1\n %.6lf'%(-c/1./b)
else:
    d=b*b-4*a*c
    if d==0:
        print 1
        print (-b)*1.0/(2*a)
    elif d<0:
        print 0
    else:
        print 2
        print (-b-d**0.5)*1.0/(2*a)
        print (-b+d**0.5)*1.0/(2*a)

        
    