#include <stdio.h>

double   f(double),
	 sin(double),
	 sum_square(double (*)(double), int, int);

int main(void)
{
   printf("%s%.7f\n%s%.7f\n",
      " First computation: ", sum_square(sin, 2, 13),
      "Second computation: ", sum_square(f, 1, 10000));
   return 0;
}

double sum_square(double (*f)(double), int m, int n)
{
   int      k;
   double   sum = 0.0;

   for (k = m; k <= n; ++k)
      sum += f(k) * f(k);
   return sum;
}

double f(double x)
{
   return 1.0 / x;
}