View Compilation Error

0_0_28297162_24588.cpp: In function 'int main()':
0_0_28297162_24588.cpp:8:3: error: '_int64' was not declared in this scope
   _int64 n;
   ^
0_0_28297162_24588.cpp:9:18: error: 'n' was not declared in this scope
   scanf("%I64d",&n);
                  ^