/in/foo.cc: In function 'int main()':
/in/foo.cc:31:15: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  while(n=read()){
               ^
/in/foo.cc: In function 'void Euler()':
/in/foo.cc:19:9: warning: iteration 1000098 invokes undefined behavior [-Waggressive-loop-optimizations]
   if(v[i]==0){
      ~~~^
/in/foo.cc:2:35: note: within this loop
 #define rep(i,l,r) for(int i=(l);i<=(r);i++)
                                   ^
/in/foo.cc:18:2: note: in expansion of macro 'rep'
  rep(i,2,N){
  ^~~