/in/foo.cc: In function 'int main()':
/in/foo.cc:90:29: error: 'MergeSub' was not declared in this scope
  MergeSub(seqlist1, seqlist2);
                             ^
/in/foo.cc:92:21: error: 'seqlist3' was not declared in this scope
  MergeSub(seqlist1, seqlist3);
                     ^~~~~~~~