{
double a,b,c,d,h;
cout << " ye comment vase user ke numbers ro vared kone:";
cin >> a >> b >> c >> d; \\ mitoni moratabtaresh koni O har kodomo yeki yeki begiri az user.
if ( a < 0 || b < 0 || c < 0 || d < 0 )
cout <<"Error: Enter only positive number!\n";
else if (a...