/in/foo.cc: In function 'void init()':
/in/foo.cc:58:11: warning: iteration 1001 invokes undefined behavior [-Waggressive-loop-optimizations]
   a[i][0] = 1;
   ~~~~~~~~^~~
/in/foo.cc:56:20: note: within this loop
  for (int i = 1; i <= 1002; ++i)
                  ~~^~~~~~~