/in/foo.cc: In function 'int main()':
/in/foo.cc:20:12: warning: iteration 10000003 invokes undefined behavior [-Waggressive-loop-optimizations]
   if(!pr7[i])pr7[temp]=i,temp=i;
       ~~~~~^
/in/foo.cc:19:15: note: within this loop
  for(int i=2;i<=maxx;i++){
               ^
/in/foo.cc:15:12: warning: iteration 10000004 invokes undefined behavior [-Waggressive-loop-optimizations]
   if(!pr7[i]&&check(i))
       ~~~~~^
/in/foo.cc:14:15: note: within this loop
  for(int i=1;i<=maxx;i++)
               ^