View Compilation Error

0_0_25572490_14606.cpp: In function 'int main()':
0_0_25572490_14606.cpp:12:2: error: 'int64' was not declared in this scope
  int64 arr[51];
  ^
0_0_25572490_14606.cpp:16:2: error: 'arr' was not declared in this scope
  arr[1]=1;arr[2]=2;
  ^