/in/foo.cc: In function 'int main()':
/in/foo.cc:60:14: warning: unused variable 'okay' [-Wunused-variable]
         bool okay;
              ^~~~
/in/foo.cc:137:9: warning: iteration 6 invokes undefined behavior [-Waggressive-loop-optimizations]
    c[j] = 0;
    ~~~~~^~~
/in/foo.cc:136:17: note: within this loop
   for (j = 1; j <= 7; ++j)
               ~~^~~~