/in/foo.cc: In function 'int main(int, const char**)':
/in/foo.cc:16:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=0;i<strlen(a);i++)
                      ^
/in/foo.cc:18:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=0;i<strlen(b);i++)
                      ^