/in/foo.cc:3:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() 
      ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:10:14: error: 'getch' was not declared in this scope
         flag=getch(); 
              ^~~~~
/in/foo.cc:10:14: note: suggested alternative: 'getc'
         flag=getch(); 
              ^~~~~
              getc
/in/foo.cc:13:13: error: 'exit' was not declared in this scope
             exit(); 
             ^~~~