/in/foo.cc: In function 'int main()':
/in/foo.cc:12:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (c.find(s1 + s2) != -1 || c.find(s2 + s1) != -1)
                             ^
/in/foo.cc:12:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (c.find(s1 + s2) != -1 || c.find(s2 + s1) != -1)
                                                      ^