View Compilation Error

0_0_8018971_27789.cpp: In function `int main(int, char**)':
0_0_8018971_27789.cpp:8: error: `_int64' undeclared (first use this function)
0_0_8018971_27789.cpp:8: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_8018971_27789.cpp:8: error: expected `;' before "ans"
0_0_8018971_27789.cpp:10: error: `ans' undeclared (first use this function)