/in/foo.cc: In function 'bool cmp(stu, stu)':
/in/foo.cc:10:37: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   10 |         return x.ch>y.ch||x.ch==y.ch&&x.ma>y.ma;
      |                           ~~~~~~~~~~^~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:15:16: error: 'st' was not declared in this scope; did you mean 'stu'?
   15 |         cin>>n;st.resize(n);
      |                ^~
      |                stu