/in/foo.cc: In function 'int main()':
/in/foo.cc:9:16: warning: iteration 9 invokes undefined behavior [-Waggressive-loop-optimizations]
  {if(sb+30>=a[i])
             ~~~^
/in/foo.cc:8:11: note: within this loop
  for(i=0;i<=9;i++)
          ~^~~