View Compilation Error

0_0_4701285_21023.cpp: In function `int main()':
0_0_4701285_21023.cpp:6: error: `_int64' undeclared (first use this function)
0_0_4701285_21023.cpp:6: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4701285_21023.cpp:6: error: expected `;' before "m"
0_0_4701285_21023.cpp:7: error: expected `;' before "fac"
0_0_4701285_21023.cpp:8: error: `fac' undeclared (first use this function)
0_0_4701285_21023.cpp:17: error: `m' undeclared (first use this function)