/in/foo.cc: In function 'void OutputQWQ()':
/in/foo.cc:15:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (res k = 0; k < QWQ[i][j].size(); k++) {
                             ~~^~~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:37:17: warning: 'a2' may be used uninitialized in this function [-Wmaybe-uninitialized]
         int a1, a2;
                 ^~
/in/foo.cc:37:13: warning: 'a1' may be used uninitialized in this function [-Wmaybe-uninitialized]
         int a1, a2;
             ^~