View Compilation Error

0_0_38576106_5446.cpp: In function 'long long int qq(int)':
0_0_38576106_5446.cpp:7:2: error: '_int64' was not declared in this scope
  _int64 a[51];
  ^~~~~~
0_0_38576106_5446.cpp:7:2: note: suggested alternative: '_time64'
  _int64 a[51];
  ^~~~~~
  _time64
0_0_38576106_5446.cpp:8:2: error: 'a' was not declared in this scope
  a[0] = 0; a[1] = 1;
  ^