/in/foo.cc: In function 'int main()':
/in/foo.cc:13:14: warning: 'ma' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<A(b,nb)<<endl;
              ^
/in/foo.cc:12:17: warning: 'ma' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<A(a,na)<<" ";
                 ^~~
/in/foo.cc: In function 'int A(int*, int)':
/in/foo.cc:36:9: warning: 'ma' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return ma;
         ^~