View Compilation Error

0_0_7093383_4472.cpp: In function `int main()':
0_0_7093383_4472.cpp:4: error: `__int64int64' undeclared (first use this function)
0_0_7093383_4472.cpp:4: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_7093383_4472.cpp:4: error: expected `;' before "sum"
0_0_7093383_4472.cpp:5: error: expected `;' before "n"
0_0_7093383_4472.cpp:6: error: `sum' undeclared (first use this function)
0_0_7093383_4472.cpp:7: error: `i' undeclared (first use this function)
0_0_7093383_4472.cpp:14: error: `n' undeclared (first use this function)