#include<stdio.h>
#include<conio.h>
#include<math.h>
#define ESP 0.0001
#define F(x) (x)*(exp(x)) = 1
#define X(x) (exp(-x))
#define G(x) -(exp(x))


void main()
{
  float x1,x2,x;
  int i=1;
  clrscr();
  do
  {
  printf("\nEnter the value of x: ");
  scanf("%f",&x);
  }while(fabs(G(x)) > 1);
  x1=X(x);
  printf("\n x = %f",x1);
  printf("\n\n");
  do
  {
   x2=X(x1);
   if(fabs(x1-x2)<ESP)
   {
    printf("\n\nREAL ROOT = %.3f",x1);
    i=0;
   }
   else
   {
    x1=x2;
   }
  if(i==1)
  {
   printf("\n x = %f",x1);
   printf("\n\n");
  }
  }while(i!=0);
getch();
}

/*
____________________________

     OUT PUT
____________________________



Enter the value of x: 90

 x = 1.275963


 x = 1.645290


 x = 1.462788


 x = 1.553900


 x = 1.508448


 x = 1.531154


 x = 1.519816


 x = 1.525479


 x = 1.522651


 x = 1.524063


 x = 1.523358


 x = 1.523710


 x = 1.523534



REAL ROOT = 1.524


*/