/in/foo.cc: In function 'int su(int)':
/in/foo.cc:6:9: warning: unused variable 'b' [-Wunused-variable]
    6 |     int b = 0;
      |         ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:16:15: warning: unused variable 'z' [-Wunused-variable]
   16 |     int x, y, z = 0;
      |               ^