View Compilation Error

0_0_14208375_30136.cpp:3:1: error: '_int64' does not name a type
 _int64 hannota(int n)
 ^
0_0_14208375_30136.cpp: In function 'int main()':
0_0_14208375_30136.cpp:19:2: error: '_int64' was not declared in this scope
  _int64 x;
  ^
0_0_14208375_30136.cpp:22:3: error: 'x' was not declared in this scope
   x=hannota(n);
   ^
0_0_14208375_30136.cpp:22:14: error: 'hannota' was not declared in this scope
   x=hannota(n);
              ^