foo.cc: In function ‘bool cmp(student, student)’:
foo.cc:22:57: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]
   22 |         return x.sumzf()>y.sumzf()||x.sumzf()==y.sumzf()&&x.sumcm()>y.sumcm()||x.sumzf()==y.sumzf()&&x.sumcm()==y.sumcm()&&x.sumh()>y.sumh();
      |                                     ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
foo.cc:22:122: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]
   22 |         return x.sumzf()>y.sumzf()||x.sumzf()==y.sumzf()&&x.sumcm()>y.sumcm()||x.sumzf()==y.sumzf()&&x.sumcm()==y.sumcm()&&x.sumh()>y.sumh();
      |                                                                                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~