/in/foo.cc: In function 'int main()':
/in/foo.cc:8:10: warning: iteration 6 invokes undefined behavior [-Waggressive-loop-optimizations]
   ans=a[i]+b[i];
       ~~~^
/in/foo.cc:7:15: note: within this loop
  for(int i=1;i<=7;i++){
              ~^~~