import time

def f(x):
  return x*x-2
  
a = float(input("input a: ")) 
b = float(input("input b: "))
e = float(input("input error: "))
if  a==b or e<=0:
  print('Iinvalid input date')

fa = f(a)
if (fa == 0): 
  print('x = ',a) 

fb = f(b) 
if (fb == 0): 
  print('x = ',b)
    
if fa*fb > 0: 
  print('Probably no solution');

if fa*fb < 0: 
  fc=fa
  while (abs(b-a) >= e) and (fc!=0) :
    c=(a+b)/2
    fc=f(c)
    if (fc*fa > 0): 
      a = c 
    else :
      b = c
  print('x = ',c)
time.sleep(2)