#include <iostream.h>
#include <math.h>
#include <errno.h>
#include <limits.h>

class ArithXcpt
{   public:
      ArithXcpt(char * msg)
      : err(msg) {}
      char * error_msg() { return err; }
    private:
      char *err;
};

inline int ABS(int r)
       {  return( r > 0 ? r : -r );  }

int gcd(int a, int b)
{       if ( a==0 && b==0 )
                throw(ArithXcpt("gcd: gcd(0,0) undefined"));
        a = ABS(a);
        b = ABS(b);
        if ( a == 0 ) return(b);    // 0 is error value
        if ( b == 0 ) return(a);
	int t;
        while ( b > 0 )
        {   t = a % b;
            a = b;
            b = t;
        }
        return (a);
}

double mysqrt(double a)
{    double ans = sqrt(a);
     if ( errno > 0 && errno == EDOM )
                throw(ArithXcpt("sqrt: domain error"));
     return(ans);
}

int mymain()
{    gcd(5,0);
     int a =17;
     a += INT_MAX;
     cerr << a << endl;
     mysqrt(-9);
     return(0);
}
	   
int main()
{     try { return( mymain() ) ; }
      catch ( ArithXcpt& a )
      {    cerr << a.error_msg() << endl;
	   return(1);
      }
      return(0);
}