Main.cc: In function 'int main()':
Main.cc:16:5: error: 'duoble' was not declared in this scope
duoble a,b;
^
Main.cc:17:10: error: 'a' was not declared in this scope
cin>>a>>b;
^
Main.cc:17:13: error: 'b' was not declared in this scope
cin>>a>>b;
^