#include<stdio.h>
 
double r(float x, int n){
	return n==0?x: (r(x,n-1)+x/r(x,n-1))/2;
}
int main(int argc, char const *argv[])
{
	float x;
	printf("the square root of %f is: %lf\n",x
,r
(x
,30.0)); 	return 0;
}
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