/in/foo.cc: In function 'int main()':
/in/foo.cc:13:16: warning: 'z' may be used uninitialized [-Wmaybe-uninitialized]
   13 |          cout<<z;
      |                ^
/in/foo.cc:5:15: note: 'z' was declared here
    5 |         int n,z,y=0;
      |               ^