View Compilation Error

0_0_4474373_25812.cpp: In function `int main()':
0_0_4474373_25812.cpp:7: error: `_int64' undeclared (first use this function)
0_0_4474373_25812.cpp:7: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4474373_25812.cpp:7: error: expected `;' before "num"
0_0_4474373_25812.cpp:11: error: `max' undeclared (first use this function)
0_0_4474373_25812.cpp:12: error: `sum' undeclared (first use this function)
0_0_4474373_25812.cpp:14: error: `num' undeclared (first use this function)