# -*- coding: utf-8 -*-


import math

def secant (f,x1,x2,tol=0.0001,maxiter=100):
    for iteration in range(maxiter):
        xnew = x2- (x2-x1)/(f(x2)-f(x1))*f(x2)
        if abs(xnew-x2)<tol: break
        else:
            x1=x2
            x2=xnew
            
    else:
        print("Warning:Maximum number of iterations is reached!")
    return xnew, iteration

f= lambda x: math.exp(-x)-x
x1= float(input("Enter x1:"))
x2= float(input("Enter x2:"))

x=secant(f,x1,x2)

print("(Root,Number of Iteration)= ",x)