class sample                                              
{                                                                
  int a;                                                         
  int b;                                                          
public:                                                          
   void setvalue()                                           
    {                                                             
      a=25; b=40;
     }
friend float mean(sample s);
};
 float mean(sample s)
   {
     return float ( s.a + s.b )/2.0;
    }

int main()
{
  sample X;                          
X.setvalue();                                                         
cout << “mean value= ”<< mean(X);                                                    
   return(0);
}

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