foo.cc: In function ‘int main()’:
foo.cc:14:38: error: ‘all’ was not declared in this scope
   14 |                         cout<<i<<" ",all=0;
      |                                      ^~~
foo.cc:16:12: error: ‘all’ was not declared in this scope
   16 |         if(all==1)cout<<n;
      |            ^~~