View Compilation Error

0_0_2724229_17027.cpp: In function `int main()':
0_0_2724229_17027.cpp:6: error: `_int64' undeclared (first use this function)
0_0_2724229_17027.cpp:6: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_2724229_17027.cpp:6: error: expected `;' before "n"
0_0_2724229_17027.cpp:7: error: `n' undeclared (first use this function)
0_0_2724229_17027.cpp:9: error: `num' undeclared (first use this function)
0_0_2724229_17027.cpp:19: error: `i' undeclared (first use this function)
0_0_2724229_17027.cpp:20: error: `j' undeclared (first use this function)