View Compilation Error

0_0_16062652_14115.cpp: In function 'int main()':
0_0_16062652_14115.cpp:5:2: error: '_int64' was not declared in this scope
  _int64 n;
  ^
0_0_16062652_14115.cpp:23:19: error: 'n' was not declared in this scope
    scanf("%I64d",&n);
                   ^