View Compilation Error

0_0_39386907_6564.cpp:5:9: error: '_int64' does not name a type
    5 |         _int64 f[50];
      |         ^~~~~~
0_0_39386907_6564.cpp: In member function 'void mm::fun()':
0_0_39386907_6564.cpp:10:13: error: 'f' was not declared in this scope
   10 |             f[0]=0;
      |             ^