/in/foo.cc: In function 'int main()':
/in/foo.cc:10:19: warning: iteration 5 invokes undefined behavior [-Waggressive-loop-optimizations]
   if(meter+30>=a[i]) cnt++;
                ~~~^
/in/foo.cc:9:15: note: within this loop
  for(int i=0;i<10;i++){
              ~^~~