View Compilation Error

24012_0_27997.cpp: In function `int main()':
24012_0_27997.cpp:11: error: `longlong' undeclared (first use this function)
24012_0_27997.cpp:11: error: (Each undeclared identifier is reported only once for each function it appears in.)
24012_0_27997.cpp:11: error: expected `;' before "n"
24012_0_27997.cpp:13: error: expected `;' before "sum"
24012_0_27997.cpp:17: error: `n' undeclared (first use this function)
24012_0_27997.cpp:19: error: `sum' undeclared (first use this function)
24012_0_27997.cpp: At global scope:
24012_0_27997.cpp:29: error: `longlong' does not name a type
tal error