/in/foo.cc: In function 'bool cli()':
/in/foo.cc:24:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < x.size(); i++)
                     ~~^~~~~~~~~~
/in/foo.cc:27:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < y.size(); i++)
                     ~~^~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:109:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int i = 4; i < s.size(); i++)
                             ~~^~~~~~~~~~
/in/foo.cc: In function 'bool cli()':
/in/foo.cc:29:21: warning: 'yy' may be used uninitialized in this function [-Wmaybe-uninitialized]
             yy = yy * 10 + y[i] - '0';
                  ~~~^~~~
/in/foo.cc:26:21: warning: 'xx' may be used uninitialized in this function [-Wmaybe-uninitialized]
             xx = xx * 10 + x[i] - '0';
                  ~~~^~~~