View Compilation Error

0_0_14712373_6564.cpp:4:1: error: '_int64' does not name a type
 _int64 actual(_int64 reading);
 ^
0_0_14712373_6564.cpp: In function 'int main()':
0_0_14712373_6564.cpp:8:2: error: '_int64' was not declared in this scope
  _int64 reading, running, power10, temp, faulty,ten;
  ^
0_0_14712373_6564.cpp:11:18: error: 'reading' was not declared in this scope
  scanf("%I64d", &reading);
                  ^
0_0_14712373_6564.cpp:14:3: error: 'running' was not declared in this scope
   running = actual(reading);
   ^
0_0_14712373_6564.cpp:14:27: error: 'actual' was not declared in this scope
   running = actual(reading);
                           ^
0_0_14712373_6564.cpp: At global scope:
0_0_14712373_6564.cpp:22:1: error: '_int64' does not name a type
 _int64 actual(_int64 reading)
 ^