foo.cc:7:9: error: expected initializer before ‘cin’
    7 |         cin>>n;
      |         ^~~
foo.cc:8:9: error: expected unqualified-id before ‘if’
    8 |         if(n==1||n==2)
      |         ^~
foo.cc:10:9: error: expected unqualified-id before ‘for’
   10 |         for(int i=3;i<=n;i++)
      |         ^~~
foo.cc:10:21: error: ‘i’ does not name a type
   10 |         for(int i=3;i<=n;i++)
      |                     ^
foo.cc:10:26: error: ‘i’ does not name a type
   10 |         for(int i=3;i<=n;i++)
      |                          ^
foo.cc:12:9: error: ‘cout’ does not name a type
   12 |         cout<<a[n];
      |         ^~~~
foo.cc:13:9: error: expected unqualified-id before ‘return’
   13 |         return 0;
      |         ^~~~~~
foo.cc:14:1: error: expected declaration before ‘}’ token
   14 | }
      | ^