#include <stdio.h>
#include <math.h>

double a=0, b=5;

double f(double x){
	return x*x;
}

double S(int n){
	double h=(b-a)/n;
	double r=(f(a)+f(b))/2;
	int k;
	for(k=1;k<n;k++) r+=f(a+k*h);
	return h*r;
}

int main(){
	double s10=S(10),s20=S(20);
	printf("s10=%24.15e\n",s10);
	printf("s20=%24.15e\n",s20);
	printf("Simp=%24.15e\n",
		 (4*s20-s10)/3);
	return 0;
}