import math
A,B,C=map(int,raw_input().split())
d=B*B-4*A*C
if A==0:
    if B==0:
        if C==0: print -1
        else: print 0
    print float(-C)/B
elif d<0: print -1
elif d==0:
    print 1
    print float(-B)/(2*A)
else:
    print 2
    print (float(-B)-math.sqrt(d))/(2*A)
    print (float(-B)+math.sqrt(d))/(2*A)