View Compilation Error

0_0_38563261_3492.cpp:3:8: error: '_int64' does not name a type
 inline _int64 fhan(int n)
        ^
0_0_38563261_3492.cpp: In function 'int main()':
0_0_38563261_3492.cpp:22:17: error: 'fhan' was not declared in this scope
   cout << fhan(n) << endl;
                 ^