answer.code:7:1: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type]
    7 | main(){
      | ^~~~
answer.code: In function ‘int main()’:
answer.code:12:31: error: ‘n’ was not declared in this scope; did you mean ‘yn’?
   12 |                         cout<<n;
      |                               ^
      |                               yn
answer.code:21:30: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   21 |                         scanf("%lld",&a[i]);
      |                         ~~~~~^~~~~~~~~~~~~~
answer.code:25:30: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   25 |                         scanf("%lld",&b[i]);
      |                         ~~~~~^~~~~~~~~~~~~~