int main ()
{
 int n;
 float a, b;
 a = ?;
 b = ?;
 float h = (b - a)/n;
 float f = 0;
 for(int i=0;i<n;i++){
  float c = a + (i - 1/2) * h;
  f = f + c/(c*c);
 }
}