#include <stdio.h>
#include <iostream>
using namespace std;
double abs1(double a)
{
return a>=0?a:-a;
}
int main()
{
double a,m,e=1e-6;
int i=0;
printf("Please input number:");
scanf("%lf",&a);
if(a<0)
{
cout<<"Please input positive value.\n";
return -1;
};
m=a/2;
while(1)
{
if(abs1(m*m-a)>e)
m=(m+(a/m))/2;
else
break;
}
cout<<m*m-a<<endl;
printf("The sqrt of a is :%f",m);
return 0;
}