#include <stdio.h>

void print_pi();

int main (int argc, char *argv[] )
{
   print_pi();

   return 0;
}

void print_pi ( )
{
   double i, pi, qp = 0.0;

   double sign = 1.0;

   for ( i = 1.0 ; i < 10000000 ; i += 2)
   {
      qp += ( sign / i ) ;
      sign = -sign ;
   }

   pi = 4 * qp ;
   printf ( "Approximate value of pi is %1.7f\n", pi ) ;
}