﻿from math import *
def f(x):
  return (25*x-32)*exp(-x)
def d():
  a=4
  b=5
  while(b-a)>0.1:
    y=f((a+b)/2)
    if y>1:
      a=(a+b)/2
    else:
      b=(a+b)/2
  return b





