View Compilation Error

0_0_20780929_1482.cpp: In function 'int main()':
0_0_20780929_1482.cpp:4:2: error: '_int64' was not declared in this scope
  _int64 n,i,a[50];
  ^
0_0_20780929_1482.cpp:5:23: error: 'n' was not declared in this scope
  while(scanf("%I64d",&n)!=EOF)
                       ^
0_0_20780929_1482.cpp:7:3: error: 'a' was not declared in this scope
   a[0]=0;
   ^
0_0_20780929_1482.cpp:10:7: error: 'i' was not declared in this scope
   for(i=4;i<=n;i++)
       ^