/in/foo.cc: In function 'int f(int)':
/in/foo.cc:10:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < g.length(); i++)
                    ^
/in/foo.cc:20:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if (n >= a || m >= a)
         ^
/in/foo.cc:20:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if (n >= a || m >= a)
                   ^