View Compilation Error

0_0_3847696_20192.cpp: In function `int main(int, char**)':
0_0_3847696_20192.cpp:5: error: `_int64' undeclared (first use this function)
0_0_3847696_20192.cpp:5: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_3847696_20192.cpp:5: error: expected `;' before "a"
0_0_3847696_20192.cpp:6: error: expected `;' before "i"
0_0_3847696_20192.cpp:7: error: `a' undeclared (first use this function)
0_0_3847696_20192.cpp:9: error: `i' undeclared (first use this function)
0_0_3847696_20192.cpp:13: error: `n' undeclared (first use this function)