View Compilation Error

0_0_16858262_18304.cpp: In function 'int main()':
0_0_16858262_18304.cpp:6:5: error: '_int64' was not declared in this scope
     _int64 arr[21];  
     ^
0_0_16858262_18304.cpp:8:5: error: 'arr' was not declared in this scope
     arr[1]=0;arr[2]=1;  
     ^