/in/foo.cc: In function 'int main()':
/in/foo.cc:5:15: warning: right operand of comma operator has no effect [-Wunused-value]
    5 |     cin >> n,p;
      |               ^
/in/foo.cc:16:11: warning: 'p' may be used uninitialized [-Wmaybe-uninitialized]
   16 |     printf("%.2f\n",p);
      |     ~~~~~~^~~~~~~~~~~~
/in/foo.cc:4:13: note: 'p' was declared here
    4 |     float n,p;
      |             ^