View Compilation Error

0_0_36734866_8805.cpp: In function 'int main()':
0_0_36734866_8805.cpp:6:2: error: '_int64' was not declared in this scope
  _int64 a,b;
  ^
0_0_36734866_8805.cpp:7:29: error: 'a' was not declared in this scope
  while(~scanf("%I64x%I64X",&a,&b))
                             ^
0_0_36734866_8805.cpp:7:32: error: 'b' was not declared in this scope
  while(~scanf("%I64x%I64X",&a,&b))
                                ^