/in/foo.cc: In function 'int main()':
/in/foo.cc:11:15: warning: iteration 9 invokes undefined behavior [-Waggressive-loop-optimizations]
   if(k+30>=a[i])
            ~~~^
/in/foo.cc:9:15: note: within this loop
  for(int i=1;i<=10;i++)
              ~^~~~