View Compilation Error

0_0_6514681_22514.cpp: In function `int main()':
0_0_6514681_22514.cpp:30: error: `_int64' undeclared (first use this function)
0_0_6514681_22514.cpp:30: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6514681_22514.cpp:30: error: expected `;' before "maxnum"
0_0_6514681_22514.cpp:40: error: expected `;' before "ans"
0_0_6514681_22514.cpp:42: error: `ans' undeclared (first use this function)
0_0_6514681_22514.cpp:43: error: `maxnum' undeclared (first use this function)