View Compilation Error

0_0_17991462_32257.cpp:2:1: error: '_int64' does not name a type
 _int64 f(_int64 n)
 ^
0_0_17991462_32257.cpp: In function 'int main()':
0_0_17991462_32257.cpp:15:2: error: '_int64' was not declared in this scope
  _int64 n,a[10000];
  ^
0_0_17991462_32257.cpp:16:7: error: 'n' was not declared in this scope
   for(n=1;n<=4018;n++)
       ^
0_0_17991462_32257.cpp:17:7: error: 'a' was not declared in this scope
       a[n]=f(n)%2009;
       ^
0_0_17991462_32257.cpp:17:15: error: 'f' was not declared in this scope
       a[n]=f(n)%2009;
               ^
0_0_17991462_32257.cpp:18:20: error: 'n' was not declared in this scope
  while(scanf("%d",&n)&&n!=0){
                    ^
0_0_17991462_32257.cpp:19:26: error: 'a' was not declared in this scope
            printf("%d\n",a[n%4018]);
                          ^