/in/foo.cc: In function 'int main()':
/in/foo.cc:10:29: warning: iteration 9 invokes undefined behavior [-Waggressive-loop-optimizations]
   10 |                 if(n+30>=a[i])sum++;
      |                          ~~~^
/in/foo.cc:9:22: note: within this loop
    9 |         for(int i=1;i<=10;i++){
      |                     ~^~~~