#include <iostream>

using namespace std;

double bendingMoment(double x, double w, double l);

void prettyPrintDouble(double x){
  char tmp[21];
  sprintf(tmp, "%10.2lf", x);
  cout << tmp;
  return;
}

int main(){
  
  double x, w, l;
  double moment;

  cout << "Enter x (distance of w), w (weight), and l (beam length)" << endl;
  cin >> x >> w >> l;
  cout << "x = " << x << ", w = " << w << ", l = " << l << endl;

  if(w < 0){
    cout << "Weight: " << w << " cannot be negative" << endl;
  }
  if(l < 0){
    cout << "Length l: " << l << " cannot be negative" << endl;
  }
  if(l < x){
    cout << "Length l : " << l << " cannot be less than x: " << x << endl;
  }
  if(x < 0){
    cout << "Length x: " << x << " cannot be negative" << endl;
  }

  if(!(w < 0 || l < 0 || l < x || x < 0)){
    moment = bendingMoment(x, w, l);
    cout << "The maximum bending moment for distance " << x << " is:  " 
	 << moment << endl;
    moment = bendingMoment(0.5 * x, w, l);
    cout << "The maximum bending moment for distance " << x/2.0 << " is:  " 
	 << moment << endl;
    return 0;
  } else {
    cerr << "Error in input, Exiting..." << endl;
    return -1;
  }
}

double bendingMoment(double x, double w, double l){
  return  x * w * (l - x) / l ;
}