Main.cc: In function ‘int main()’:
Main.cc:9:5: error: ‘cin’ was not declared in this scope
cin >> n;
^~~
Main.cc:9:5: note: suggested alternative: ‘sin’
cin >> n;
^~~
sin
Main.cc:18:5: error: ‘cout’ was not declared in this scope
cout << pi << endl;
^~~~
Main.cc:18:5: note: suggested alternative: ‘cosl’
cout << pi << endl;
^~~~
cosl
Main.cc:18:19: error: ‘endl’ was not declared in this scope
cout << pi << endl;
^~~~
Main.cc:18:19: note: suggested alternative: ‘ynl’
cout << pi << endl;
^~~~
ynl